256603217490 has 256 divisors, whose sum is σ = 747590860800. Its totient is φ = 62430407424.

The previous prime is 256603217483. The next prime is 256603217527. The reversal of 256603217490 is 94712306652.

256603217490 is a `hidden beast` number, since 2 + 566 + 0 + 32 + 17 + 49 + 0 = 666.

It is a super-2 number, since 2×256603217490² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 14938887 + ... + 14956053.

It is an arithmetic number, because the mean of its divisors is an integer number (2920276800).

Almost surely, 2^256603217490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256603217490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373795430400).

256603217490 is an abundant number, since it is smaller than the sum of its proper divisors (490987643310).

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

256603217490 is a wasteful number, since it uses less digits than its factorization.

256603217490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17318 (or 17312 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 256603217490 in words is "two hundred fifty-six billion, six hundred three million, two hundred seventeen thousand, four hundred ninety".