647540256 has 96 divisors (see below), whose sum is σ = 1904551488. Its totient is φ = 190909440.

The previous prime is 647540239. The next prime is 647540261. The reversal of 647540256 is 652045746.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30786 + ... + 47358.

It is an arithmetic number, because the mean of its divisors is an integer number (19839078).

Almost surely, 2^647540256 is an apocalyptic number.

647540256 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647540256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (952275744).

647540256 is an abundant number, since it is smaller than the sum of its proper divisors (1257011232).

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

647540256 is a wasteful number, since it uses less digits than its factorization.

647540256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16634 (or 16626 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 39.

The square root of 647540256 is about 25446.8122954526. The cubic root of 647540256 is about 865.1450438946.

The spelling of 647540256 in words is "six hundred forty-seven million, five hundred forty thousand, two hundred fifty-six".