639291534523 has 4 divisors (see below), whose sum is σ = 639294683200. Its totient is φ = 639288385848.

The previous prime is 639291534467. The next prime is 639291534593. The reversal of 639291534523 is 325435192936.

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-639291534523 is a prime.

It is a super-2 number, since 2×639291534523² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639291534593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1247115 + ... + 1683412.

It is an arithmetic number, because the mean of its divisors is an integer number (159823670800).

Almost surely, 2^639291534523 is an apocalyptic number.

639291534523 is a deficient number, since it is larger than the sum of its proper divisors (3148677).

639291534523 is a wasteful number, since it uses less digits than its factorization.

639291534523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3148676.

The product of its digits is 5248800, while the sum is 52.

The spelling of 639291534523 in words is "six hundred thirty-nine billion, two hundred ninety-one million, five hundred thirty-four thousand, five hundred twenty-three".