256478990 has 16 divisors (see below), whose sum is σ = 463736448. Its totient is φ = 102130656.

The previous prime is 256478947. The next prime is 256478993. The reversal of 256478990 is 99874652.

It is a happy number.

It is a super-2 number, since 2×256478990² = 131562944622840200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256478993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55277 + ... + 59736.

It is an arithmetic number, because the mean of its divisors is an integer number (28983528).

Almost surely, 2^256478990 is an apocalyptic number.

256478990 is a deficient number, since it is larger than the sum of its proper divisors (207257458).

256478990 is a wasteful number, since it uses less digits than its factorization.

256478990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115243.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The square root of 256478990 is about 16014.9614423513. The cubic root of 256478990 is about 635.3561892789.

The spelling of 256478990 in words is "two hundred fifty-six million, four hundred seventy-eight thousand, nine hundred ninety".