639522817663 has 4 divisors (see below), whose sum is σ = 639549860760. Its totient is φ = 639495774568.

The previous prime is 639522817657. The next prime is 639522817679. The reversal of 639522817663 is 366718225936.

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-639522817663 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639522817598 and 639522817607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639522817613) 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, 13486045 + ... + 13533382.

It is an arithmetic number, because the mean of its divisors is an integer number (159887465190).

Almost surely, 2^639522817663 is an apocalyptic number.

639522817663 is a deficient number, since it is larger than the sum of its proper divisors (27043097).

639522817663 is a wasteful number, since it uses less digits than its factorization.

639522817663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27043096.

The product of its digits is 19595520, while the sum is 58.

The spelling of 639522817663 in words is "six hundred thirty-nine billion, five hundred twenty-two million, eight hundred seventeen thousand, six hundred sixty-three".