256447555 has 32 divisors (see below), whose sum is σ = 389015424. Its totient is φ = 157925376.

The previous prime is 256447553. The next prime is 256447561. The reversal of 256447555 is 555744652.

It is not a de Polignac number, because 256447555 - 2¹ = 256447553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256447553) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9219 + ... + 24451.

It is an arithmetic number, because the mean of its divisors is an integer number (12156732).

Almost surely, 2^256447555 is an apocalyptic number.

256447555 is a deficient number, since it is larger than the sum of its proper divisors (132567869).

256447555 is a wasteful number, since it uses less digits than its factorization.

256447555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15295.

The product of its digits is 840000, while the sum is 43.

The square root of 256447555 is about 16013.9799862495. The cubic root of 256447555 is about 635.3302310281.

The spelling of 256447555 in words is "two hundred fifty-six million, four hundred forty-seven thousand, five hundred fifty-five".