647201664 has 80 divisors (see below), whose sum is σ = 1926092520. Its totient is φ = 215730432.

The previous prime is 647201629. The next prime is 647201719. The reversal of 647201664 is 466102746.

647201664 is a `hidden beast` number, since 647 + 2 + 0 + 1 + 6 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 20844 + ... + 41579.

Almost surely, 2^647201664 is an apocalyptic number.

647201664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

647201664 is an abundant number, since it is smaller than the sum of its proper divisors (1278890856).

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

647201664 is an equidigital number, since it uses as much as digits as its factorization.

647201664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62449 (or 62428 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 647201664 is about 25440.1584900723. The cubic root of 647201664 is about 864.9942258516.

The spelling of 647201664 in words is "six hundred forty-seven million, two hundred one thousand, six hundred sixty-four".