256990390 has 32 divisors (see below), whose sum is σ = 491436000. Its totient is φ = 96484608.

The previous prime is 256990381. The next prime is 256990399. The reversal of 256990390 is 93099652.

It is an interprime number because it is at equal distance from previous prime (256990381) and next prime (256990399).

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256990399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14506 + ... + 26914.

It is an arithmetic number, because the mean of its divisors is an integer number (15357375).

Almost surely, 2^256990390 is an apocalyptic number.

256990390 is a deficient number, since it is larger than the sum of its proper divisors (234445610).

256990390 is a wasteful number, since it uses less digits than its factorization.

256990390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12544.

The product of its (nonzero) digits is 131220, while the sum is 43.

The square root of 256990390 is about 16030.9198114144. The cubic root of 256990390 is about 635.7781932254.

The spelling of 256990390 in words is "two hundred fifty-six million, nine hundred ninety thousand, three hundred ninety".