639876541 has 4 divisors (see below), whose sum is σ = 639964000. Its totient is φ = 639789084.

The previous prime is 639876533. The next prime is 639876551. The reversal of 639876541 is 145678936.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639876541 - 2³ = 639876533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639876551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31641 + ... + 47758.

It is an arithmetic number, because the mean of its divisors is an integer number (159991000).

Almost surely, 2^639876541 is an apocalyptic number.

It is an amenable number.

639876541 is a deficient number, since it is larger than the sum of its proper divisors (87459).

639876541 is an equidigital number, since it uses as much as digits as its factorization.

639876541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87458.

The product of its digits is 1088640, while the sum is 49.

The square root of 639876541 is about 25295.7810909250. The cubic root of 639876541 is about 861.7184590425.

The spelling of 639876541 in words is "six hundred thirty-nine million, eight hundred seventy-six thousand, five hundred forty-one".