647565881 has 8 divisors (see below), whose sum is σ = 653361984. Its totient is φ = 641782960.

The previous prime is 647565871. The next prime is 647565901. The reversal of 647565881 is 188565746.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 647565881 - 2⁶ = 647565817 is a prime.

It is a super-2 number, since 2×647565881² = 838683140470612322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647565871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113411 + ... + 118983.

It is an arithmetic number, because the mean of its divisors is an integer number (81670248).

Almost surely, 2^647565881 is an apocalyptic number.

It is an amenable number.

647565881 is a deficient number, since it is larger than the sum of its proper divisors (5796103).

647565881 is a wasteful number, since it uses less digits than its factorization.

647565881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6591.

The product of its digits is 1612800, while the sum is 50.

The square root of 647565881 is about 25447.3157916508. The cubic root of 647565881 is about 865.1564558231.

The spelling of 647565881 in words is "six hundred forty-seven million, five hundred sixty-five thousand, eight hundred eighty-one".