639993600016 has 15 divisors (see below), whose sum is σ = 1239993800031. Its totient is φ = 319995200016.

The previous prime is 639993599989. The next prime is 639993600017. The reversal of 639993600016 is 610006399936.

The square root of 639993600016 is 799996.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×639993600016² (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 (639993600017) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3099985 + ... + 3299983.

Almost surely, 2^639993600016 is an apocalyptic number.

639993600016 is the 799996-th square number.

It is an amenable number.

639993600016 is a deficient number, since it is larger than the sum of its proper divisors (600000200015).

639993600016 is an frugal number, since it uses more digits than its factorization.

639993600016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400006 (or 200001 counting only the distinct ones).

The product of its (nonzero) digits is 1417176, while the sum is 52.

The spelling of 639993600016 in words is "six hundred thirty-nine billion, nine hundred ninety-three million, six hundred thousand, sixteen".