642684879 has 12 divisors (see below), whose sum is σ = 929229600. Its totient is φ = 428037984.

The previous prime is 642684869. The next prime is 642684941. The reversal of 642684879 is 978486246.

It is not a de Polignac number, because 642684879 - 2¹⁵ = 642652111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642684859) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25014 + ... + 43715.

It is an arithmetic number, because the mean of its divisors is an integer number (77435800).

Almost surely, 2^642684879 is an apocalyptic number.

642684879 is a deficient number, since it is larger than the sum of its proper divisors (286544721).

642684879 is a wasteful number, since it uses less digits than its factorization.

642684879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69774 (or 69771 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The square root of 642684879 is about 25351.2303251736. The cubic root of 642684879 is about 862.9772773676.

The spelling of 642684879 in words is "six hundred forty-two million, six hundred eighty-four thousand, eight hundred seventy-nine".