256425642 has 32 divisors (see below), whose sum is σ = 621639360. Its totient is φ = 77704560.

The previous prime is 256425619. The next prime is 256425647. The reversal of 256425642 is 246524652.

256425642 is a `hidden beast` number, since 2 + 5 + 6 + 4 + 2 + 5 + 642 = 666.

It is a super-2 number, since 2×256425642² = 131508219750224328, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256425597 and 256425606.

It is not an unprimeable number, because it can be changed into a prime (256425647) 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, 215253 + ... + 216440.

It is an arithmetic number, because the mean of its divisors is an integer number (19426230).

Almost surely, 2^256425642 is an apocalyptic number.

256425642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

256425642 is an abundant number, since it is smaller than the sum of its proper divisors (365213718).

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

256425642 is a wasteful number, since it uses less digits than its factorization.

256425642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431715 (or 431709 counting only the distinct ones).

The product of its digits is 115200, while the sum is 36.

The square root of 256425642 is about 16013.2957881880. The cubic root of 256425642 is about 635.3121345562.

The spelling of 256425642 in words is "two hundred fifty-six million, four hundred twenty-five thousand, six hundred forty-two".