646153913 has 4 divisors (see below), whose sum is σ = 646672500. Its totient is φ = 645635328.

The previous prime is 646153909. The next prime is 646153933. The reversal of 646153913 is 319351646.

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

It can be written as a sum of positive squares in 2 ways, for example, as 149621824 + 496532089 = 12232^2 + 22283^2 .

It is a cyclic number.

It is not a de Polignac number, because 646153913 - 2² = 646153909 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646153933) 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, 257420 + ... + 259917.

It is an arithmetic number, because the mean of its divisors is an integer number (161668125).

Almost surely, 2^646153913 is an apocalyptic number.

It is an amenable number.

646153913 is a deficient number, since it is larger than the sum of its proper divisors (518587).

646153913 is a wasteful number, since it uses less digits than its factorization.

646153913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518586.

The product of its digits is 58320, while the sum is 38.

The square root of 646153913 is about 25419.5576869465. The cubic root of 646153913 is about 864.5271957006.

The spelling of 646153913 in words is "six hundred forty-six million, one hundred fifty-three thousand, nine hundred thirteen".