639535587923 has 4 divisors (see below), whose sum is σ = 642280376088. Its totient is φ = 636790799760.

The previous prime is 639535587913. The next prime is 639535587979. The reversal of 639535587923 is 329785535936.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639535587923 is a prime.

It is a super-3 number, since 3×639535587923³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639535587923.

It is not an unprimeable number, because it can be changed into a prime (639535587913) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1372393733 + ... + 1372394198.

It is an arithmetic number, because the mean of its divisors is an integer number (160570094022).

Almost surely, 2^639535587923 is an apocalyptic number.

639535587923 is a deficient number, since it is larger than the sum of its proper divisors (2744788165).

639535587923 is a wasteful number, since it uses less digits than its factorization.

639535587923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2744788164.

The product of its digits is 183708000, while the sum is 65.

The spelling of 639535587923 in words is "six hundred thirty-nine billion, five hundred thirty-five million, five hundred eighty-seven thousand, nine hundred twenty-three".