131221123320 has 256 divisors, whose sum is σ = 454833792000. Its totient is φ = 29666304000.

The previous prime is 131221123289. The next prime is 131221123351. The reversal of 131221123320 is 23321122131.

It is an interprime number because it is at equal distance from previous prime (131221123289) and next prime (131221123351).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 31413072 + ... + 31417248.

It is an arithmetic number, because the mean of its divisors is an integer number (1776694500).

Almost surely, 2^131221123320 is an apocalyptic number.

131221123320 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 131221123320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227416896000).

131221123320 is an abundant number, since it is smaller than the sum of its proper divisors (323612668680).

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

131221123320 is a wasteful number, since it uses less digits than its factorization.

131221123320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4598 (or 4594 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 131221123320 its reverse (23321122131), we get a palindrome (154542245451).

It can be divided in two parts, 131221 and 123320, that added together give a triangular number (254541 = T₇₁₃).

The spelling of 131221123320 in words is "one hundred thirty-one billion, two hundred twenty-one million, one hundred twenty-three thousand, three hundred twenty".