639521520089 has 4 divisors (see below), whose sum is σ = 639600374400. Its totient is φ = 639442665780.

The previous prime is 639521520067. The next prime is 639521520097. The reversal of 639521520089 is 980025125936.

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 639521520089 - 2¹² = 639521515993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639521520019) 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, 39414989 + ... + 39431210.

It is an arithmetic number, because the mean of its divisors is an integer number (159900093600).

Almost surely, 2^639521520089 is an apocalyptic number.

It is an amenable number.

639521520089 is a deficient number, since it is larger than the sum of its proper divisors (78854311).

639521520089 is an equidigital number, since it uses as much as digits as its factorization.

639521520089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78854310.

The product of its (nonzero) digits is 1166400, while the sum is 50.

The spelling of 639521520089 in words is "six hundred thirty-nine billion, five hundred twenty-one million, five hundred twenty thousand, eighty-nine".