647668069 has 4 divisors (see below), whose sum is σ = 647900640. Its totient is φ = 647435500.

The previous prime is 647668039. The next prime is 647668079. The reversal of 647668069 is 960866746.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 647668069 - 2⁷ = 647667941 is a prime.

It is a super-2 number, since 2×647668069² = 838947855204377522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647668039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112057 + ... + 117694.

It is an arithmetic number, because the mean of its divisors is an integer number (161975160).

Almost surely, 2^647668069 is an apocalyptic number.

It is an amenable number.

647668069 is a deficient number, since it is larger than the sum of its proper divisors (232571).

647668069 is a wasteful number, since it uses less digits than its factorization.

647668069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232570.

The product of its (nonzero) digits is 2612736, while the sum is 52.

The square root of 647668069 is about 25449.3235470022. The cubic root of 647668069 is about 865.2019615961.

The spelling of 647668069 in words is "six hundred forty-seven million, six hundred sixty-eight thousand, sixty-nine".