131256640 has 56 divisors (see below), whose sum is σ = 319857120. Its totient is φ = 51276288.

The previous prime is 131256637. The next prime is 131256641. The reversal of 131256640 is 46652131.

It is a junction number, because it is equal to n+sod(n) for n = 131256599 and 131256608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131256641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8991 + ... + 18529.

Almost surely, 2^131256640 is an apocalyptic number.

131256640 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 131256640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159928560).

131256640 is an abundant number, since it is smaller than the sum of its proper divisors (188600480).

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

131256640 is an equidigital number, since it uses as much as digits as its factorization.

131256640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9599 (or 9589 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 131256640 is about 11456.7290270827. The cubic root of 131256640 is about 508.2067482589.

The spelling of 131256640 in words is "one hundred thirty-one million, two hundred fifty-six thousand, six hundred forty".