646620479 has 4 divisors (see below), whose sum is σ = 649079376. Its totient is φ = 644161584.

The previous prime is 646620467. The next prime is 646620487. The reversal of 646620479 is 974026646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646620479 - 2⁸ = 646620223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646622479) 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, 1229054 + ... + 1229579.

It is an arithmetic number, because the mean of its divisors is an integer number (162269844).

Almost surely, 2^646620479 is an apocalyptic number.

646620479 is a deficient number, since it is larger than the sum of its proper divisors (2458897).

646620479 is a wasteful number, since it uses less digits than its factorization.

646620479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2458896.

The product of its (nonzero) digits is 435456, while the sum is 44.

The square root of 646620479 is about 25428.7333345568. The cubic root of 646620479 is about 864.7352276377.

The spelling of 646620479 in words is "six hundred forty-six million, six hundred twenty thousand, four hundred seventy-nine".