256417220 has 24 divisors (see below), whose sum is σ = 538876800. Its totient is φ = 102490592.

The previous prime is 256417211. The next prime is 256417237. The reversal of 256417220 is 22714652.

It is a happy number.

256417220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28421 + ... + 36339.

It is an arithmetic number, because the mean of its divisors is an integer number (22453200).

Almost surely, 2^256417220 is an apocalyptic number.

256417220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256417220 is an abundant number, since it is smaller than the sum of its proper divisors (282459580).

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

256417220 is a wasteful number, since it uses less digits than its factorization.

256417220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9547 (or 9545 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 256417220 is about 16013.0328170525. The cubic root of 256417220 is about 635.3051791190.

The spelling of 256417220 in words is "two hundred fifty-six million, four hundred seventeen thousand, two hundred twenty".