131121023220 has 216 divisors, whose sum is σ = 439457703048. Its totient is φ = 31621201920.

The previous prime is 131121023213. The next prime is 131121023227. The reversal of 131121023220 is 22320121131.

131121023220 is a `hidden beast` number, since 131 + 1 + 210 + 2 + 322 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (131121023213) and next prime (131121023227).

It can be written as a sum of positive squares in 4 ways, for example, as 4382175204 + 126738848016 = 66198^2 + 356004^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 131121023193 and 131121023202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131121023227) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 4187944 + ... + 4219136.

It is an arithmetic number, because the mean of its divisors is an integer number (2034526403).

Almost surely, 2^131121023220 is an apocalyptic number.

131121023220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131121023220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219728851524).

131121023220 is an abundant number, since it is smaller than the sum of its proper divisors (308336679828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131121023220 is a wasteful number, since it uses less digits than its factorization.

131121023220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31423 (or 31407 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 131121023220 its reverse (22320121131), we get a palindrome (153441144351).

The spelling of 131121023220 in words is "one hundred thirty-one billion, one hundred twenty-one million, twenty-three thousand, two hundred twenty".