131220520 has 128 divisors (see below), whose sum is σ = 328458240. Its totient is φ = 47013120.

The previous prime is 131220499. The next prime is 131220521. The reversal of 131220520 is 25022131.

It is a junction number, because it is equal to n+sod(n) for n = 131220494 and 131220503.

It is not an unprimeable number, because it can be changed into a prime (131220521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1226307 + ... + 1226413.

It is an arithmetic number, because the mean of its divisors is an integer number (2566080).

Almost surely, 2^131220520 is an apocalyptic number.

131220520 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 131220520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164229120).

131220520 is an abundant number, since it is smaller than the sum of its proper divisors (197237720).

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

131220520 is a wasteful number, since it uses less digits than its factorization.

131220520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 131220520 is about 11455.1525524543. The cubic root of 131220520 is about 508.1601268414.

Adding to 131220520 its reverse (25022131), we get a palindrome (156242651).

The spelling of 131220520 in words is "one hundred thirty-one million, two hundred twenty thousand, five hundred twenty".