3996973681 has 2 divisors, whose sum is σ = 3996973682. Its totient is φ = 3996973680.

The previous prime is 3996973679. The next prime is 3996973769. The reversal of 3996973681 is 1863796993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2471680656 + 1525293025 = 49716^2 + 39055^2 .

It is a cyclic number.

It is not a de Polignac number, because 3996973681 - 2¹ = 3996973679 is a prime.

It is a super-2 number, since 2×3996973681² = 31951597213213379522, which contains 22 as substring.

Together with 3996973679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (3996971681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1998486840 + 1998486841.

It is an arithmetic number, because the mean of its divisors is an integer number (1998486841).

Almost surely, 2^3996973681 is an apocalyptic number.

It is an amenable number.

3996973681 is a deficient number, since it is larger than the sum of its proper divisors (1).

3996973681 is an equidigital number, since it uses as much as digits as its factorization.

3996973681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13226976, while the sum is 61.

The square root of 3996973681 is about 63221.6235239178. The cubic root of 3996973681 is about 1587.0006191344. Note that the first 3 decimals are identical.

The spelling of 3996973681 in words is "three billion, nine hundred ninety-six million, nine hundred seventy-three thousand, six hundred eighty-one".