642045939 has 4 divisors (see below), whose sum is σ = 856061256. Its totient is φ = 428030624.

The previous prime is 642045913. The next prime is 642045949. The reversal of 642045939 is 939540246.

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

It is a cyclic number.

It is not a de Polignac number, because 642045939 - 2⁸ = 642045683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642045939.

It is not an unprimeable number, because it can be changed into a prime (642045949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107007654 + ... + 107007659.

It is an arithmetic number, because the mean of its divisors is an integer number (214015314).

Almost surely, 2^642045939 is an apocalyptic number.

642045939 is a deficient number, since it is larger than the sum of its proper divisors (214015317).

642045939 is a wasteful number, since it uses less digits than its factorization.

642045939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214015316.

The product of its (nonzero) digits is 233280, while the sum is 42.

The square root of 642045939 is about 25338.6254362781. The cubic root of 642045939 is about 862.6911996196.

The spelling of 642045939 in words is "six hundred forty-two million, forty-five thousand, nine hundred thirty-nine".