3994997731 has 2 divisors, whose sum is σ = 3994997732. Its totient is φ = 3994997730.

The previous prime is 3994997687. The next prime is 3994997759. The reversal of 3994997731 is 1377994993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3994997731 - 2⁹ = 3994997219 is a prime.

It is a super-2 number, since 2×3994997731² = 31920013741390296722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 3994997731.

It is not a weakly prime, because it can be changed into another prime (3994997761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1997498865 + 1997498866.

It is an arithmetic number, because the mean of its divisors is an integer number (1997498866).

Almost surely, 2^3994997731 is an apocalyptic number.

3994997731 is a deficient number, since it is larger than the sum of its proper divisors (1).

3994997731 is an equidigital number, since it uses as much as digits as its factorization.

3994997731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11573604, while the sum is 61.

The square root of 3994997731 is about 63205.9944229976. The cubic root of 3994997731 is about 1586.7390586797.

The spelling of 3994997731 in words is "three billion, nine hundred ninety-four million, nine hundred ninety-seven thousand, seven hundred thirty-one".