642989644 has 18 divisors (see below), whose sum is σ = 1236826052. Its totient is φ = 292267800.

The previous prime is 642989617. The next prime is 642989647. The reversal of 642989644 is 446989246.

642989644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 642989591 and 642989600.

It is not an unprimeable number, because it can be changed into a prime (642989647) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 663762 + ... + 664729.

Almost surely, 2^642989644 is an apocalyptic number.

It is an amenable number.

642989644 is a deficient number, since it is larger than the sum of its proper divisors (593836408).

642989644 is a wasteful number, since it uses less digits than its factorization.

642989644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1328517 (or 1328504 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 52.

The square root of 642989644 is about 25357.2404650033. The cubic root of 642989644 is about 863.1136654672.

The spelling of 642989644 in words is "six hundred forty-two million, nine hundred eighty-nine thousand, six hundred forty-four".