3966721931 has 2 divisors, whose sum is σ = 3966721932. Its totient is φ = 3966721930.

The previous prime is 3966721919. The next prime is 3966721949. The reversal of 3966721931 is 1391276693.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3966721931 - 2⁶ = 3966721867 is a prime.

It is a super-2 number, since 2×3966721931² = 31469765755752737522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3966721951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1983360965 + 1983360966.

It is an arithmetic number, because the mean of its divisors is an integer number (1983360966).

Almost surely, 2^3966721931 is an apocalyptic number.

3966721931 is a deficient number, since it is larger than the sum of its proper divisors (1).

3966721931 is an equidigital number, since it uses as much as digits as its factorization.

3966721931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 47.

The square root of 3966721931 is about 62981.9174922453. The cubic root of 3966721931 is about 1582.9866505332.

The spelling of 3966721931 in words is "three billion, nine hundred sixty-six million, seven hundred twenty-one thousand, nine hundred thirty-one".