642219994 has 16 divisors (see below), whose sum is σ = 1070899200. Its totient is φ = 286847280.

The previous prime is 642219979. The next prime is 642220003. The reversal of 642219994 is 499912246.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397594 + ... + 399205.

It is an arithmetic number, because the mean of its divisors is an integer number (66931200).

Almost surely, 2^642219994 is an apocalyptic number.

642219994 is a deficient number, since it is larger than the sum of its proper divisors (428679206).

642219994 is a wasteful number, since it uses less digits than its factorization.

642219994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796845.

The product of its digits is 279936, while the sum is 46.

The square root of 642219994 is about 25342.0597821093. The cubic root of 642219994 is about 862.7691494676.

The spelling of 642219994 in words is "six hundred forty-two million, two hundred nineteen thousand, nine hundred ninety-four".