639345142 has 4 divisors (see below), whose sum is σ = 959017716. Its totient is φ = 319672570.

The previous prime is 639345137. The next prime is 639345149. The reversal of 639345142 is 241543936.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639345149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159836284 + ... + 159836287.

It is an arithmetic number, because the mean of its divisors is an integer number (239754429).

Almost surely, 2^639345142 is an apocalyptic number.

639345142 is a deficient number, since it is larger than the sum of its proper divisors (319672574).

639345142 is a wasteful number, since it uses less digits than its factorization.

639345142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319672573.

The product of its digits is 77760, while the sum is 37.

The square root of 639345142 is about 25285.2752011917. The cubic root of 639345142 is about 861.4798488738.

The spelling of 639345142 in words is "six hundred thirty-nine million, three hundred forty-five thousand, one hundred forty-two".