256631215765740 has 192 divisors, whose sum is σ = 739586783545344. Its totient is φ = 66462741430272.

The previous prime is 256631215765739. The next prime is 256631215765783. The reversal of 256631215765740 is 47567512136652.

It is a Harshad number since it is a multiple of its sum of digits (60).

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, 717917932 + ... + 718275308.

It is an arithmetic number, because the mean of its divisors is an integer number (3852014497632).

Almost surely, 2^{256631215765740} is an apocalyptic number.

256631215765740 is a gapful number since it is divisible by the number (20) 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 256631215765740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369793391772672).

256631215765740 is an abundant number, since it is smaller than the sum of its proper divisors (482955567779604).

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

256631215765740 is a wasteful number, since it uses less digits than its factorization.

256631215765740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359976 (or 359974 counting only the distinct ones).

The product of its (nonzero) digits is 63504000, while the sum is 60.

The spelling of 256631215765740 in words is "two hundred fifty-six trillion, six hundred thirty-one billion, two hundred fifteen million, seven hundred sixty-five thousand, seven hundred forty".