256992481 has 4 divisors (see below), whose sum is σ = 257209092. Its totient is φ = 256775872.

The previous prime is 256992473. The next prime is 256992497. The reversal of 256992481 is 184299652.

256992481 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 216237025 + 40755456 = 14705^2 + 6384^2 .

It is a cyclic number.

It is not a de Polignac number, because 256992481 - 2³ = 256992473 is a prime.

It is a super-2 number, since 2×256992481² = 132090270581070722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256992401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106516 + ... + 108901.

It is an arithmetic number, because the mean of its divisors is an integer number (64302273).

Almost surely, 2^256992481 is an apocalyptic number.

It is an amenable number.

256992481 is a deficient number, since it is larger than the sum of its proper divisors (216611).

256992481 is a wasteful number, since it uses less digits than its factorization.

256992481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216610.

The product of its digits is 311040, while the sum is 46.

The square root of 256992481 is about 16030.9850289993. The cubic root of 256992481 is about 635.7799175552.

The spelling of 256992481 in words is "two hundred fifty-six million, nine hundred ninety-two thousand, four hundred eighty-one".