646590813 has 16 divisors (see below), whose sum is σ = 943574016. Its totient is φ = 390590640.

The previous prime is 646590811. The next prime is 646590829. The reversal of 646590813 is 318095646.

It is not a de Polignac number, because 646590813 - 2¹ = 646590811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646590811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21781 + ... + 42042.

It is an arithmetic number, because the mean of its divisors is an integer number (58973376).

Almost surely, 2^646590813 is an apocalyptic number.

It is an amenable number.

646590813 is a deficient number, since it is larger than the sum of its proper divisors (296983203).

646590813 is a wasteful number, since it uses less digits than its factorization.

646590813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64144.

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 646590813 is about 25428.1500113555. The cubic root of 646590813 is about 864.7220031738.

The spelling of 646590813 in words is "six hundred forty-six million, five hundred ninety thousand, eight hundred thirteen".