256417645420 has 24 divisors (see below), whose sum is σ = 545293224000. Its totient is φ = 101268740352.

The previous prime is 256417645411. The next prime is 256417645447. The reversal of 256417645420 is 24546714652.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81143245 + ... + 81146404.

It is an arithmetic number, because the mean of its divisors is an integer number (22720551000).

Almost surely, 2^256417645420 is an apocalyptic number.

256417645420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256417645420 is an abundant number, since it is smaller than the sum of its proper divisors (288875578580).

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

256417645420 is a wasteful number, since it uses less digits than its factorization.

256417645420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162289737 (or 162289735 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 46.

The spelling of 256417645420 in words is "two hundred fifty-six billion, four hundred seventeen million, six hundred forty-five thousand, four hundred twenty".