647644563 has 24 divisors (see below), whose sum is σ = 993964608. Its totient is φ = 404950272.

The previous prime is 647644541. The next prime is 647644637. The reversal of 647644563 is 365446746.

It is a happy number.

647644563 is a `hidden beast` number, since 6 + 47 + 6 + 44 + 563 = 666.

It is not a de Polignac number, because 647644563 - 2⁵ = 647644531 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (647644513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37606 + ... + 52052.

It is an arithmetic number, because the mean of its divisors is an integer number (41415192).

Almost surely, 2^647644563 is an apocalyptic number.

647644563 is a deficient number, since it is larger than the sum of its proper divisors (346320045).

647644563 is a wasteful number, since it uses less digits than its factorization.

647644563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14763 (or 14760 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 45.

The square root of 647644563 is about 25448.8617230712. The cubic root of 647644563 is about 865.1914944631.

The spelling of 647644563 in words is "six hundred forty-seven million, six hundred forty-four thousand, five hundred sixty-three".