256071640 has 32 divisors (see below), whose sum is σ = 628540560. Its totient is φ = 93116800.

The previous prime is 256071637. The next prime is 256071667. The reversal of 256071640 is 46170652.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 290551 + ... + 291430.

Almost surely, 2^256071640 is an apocalyptic number.

256071640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256071640 is an abundant number, since it is smaller than the sum of its proper divisors (372468920).

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

256071640 is a wasteful number, since it uses less digits than its factorization.

256071640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582003 (or 581999 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 256071640 is about 16002.2385933969. The cubic root of 256071640 is about 635.0196451649.

The spelling of 256071640 in words is "two hundred fifty-six million, seventy-one thousand, six hundred forty".