3991996639331 has 64 divisors (see below), whose sum is σ = 4309773640704. Its totient is φ = 3691733760000.

The previous prime is 3991996639307. The next prime is 3991996639357. The reversal of 3991996639331 is 1339366991993.

It is a cyclic number.

It is not a de Polignac number, because 3991996639331 - 2²² = 3991992445027 is a prime.

It is a super-2 number, since 2×3991996639331² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3991996632331) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4260401495 + ... + 4260402431.

It is an arithmetic number, because the mean of its divisors is an integer number (67340213136).

Almost surely, 2^{3991996639331} is an apocalyptic number.

3991996639331 is a deficient number, since it is larger than the sum of its proper divisors (317777001373).

3991996639331 is a wasteful number, since it uses less digits than its factorization.

3991996639331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1500.

The product of its digits is 172186884, while the sum is 71.

The spelling of 3991996639331 in words is "three trillion, nine hundred ninety-one billion, nine hundred ninety-six million, six hundred thirty-nine thousand, three hundred thirty-one".