684639513 has 8 divisors (see below), whose sum is σ = 1014280800. Its totient is φ = 456426324.

The previous prime is 684639503. The next prime is 684639523. The reversal of 684639513 is 315936486.

684639513 is a `hidden beast` number, since 6 + 8 + 4 + 639 + 5 + 1 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (684639503) and next prime (684639523).

It is not a de Polignac number, because 684639513 - 2⁸ = 684639257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (684639503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12678483 + ... + 12678536.

It is an arithmetic number, because the mean of its divisors is an integer number (126785100).

Almost surely, 2^684639513 is an apocalyptic number.

It is an amenable number.

684639513 is a deficient number, since it is larger than the sum of its proper divisors (329641287).

684639513 is a wasteful number, since it uses less digits than its factorization.

684639513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25357028 (or 25357022 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The square root of 684639513 is about 26165.6170001779. The cubic root of 684639513 is about 881.3613197537.

The spelling of 684639513 in words is "six hundred eighty-four million, six hundred thirty-nine thousand, five hundred thirteen".