397993811 has 2 divisors, whose sum is σ = 397993812. Its totient is φ = 397993810.

The previous prime is 397993807. The next prime is 397993873. The reversal of 397993811 is 118399793.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (118399793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 397993811 - 2² = 397993807 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 397993811.

It is not a weakly prime, because it can be changed into another prime (397993891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198996905 + 198996906.

It is an arithmetic number, because the mean of its divisors is an integer number (198996906).

Almost surely, 2^397993811 is an apocalyptic number.

397993811 is a deficient number, since it is larger than the sum of its proper divisors (1).

397993811 is an equidigital number, since it uses as much as digits as its factorization.

397993811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 367416, while the sum is 50.

The square root of 397993811 is about 19949.7822293879. The cubic root of 397993811 is about 735.5724240219.

The spelling of 397993811 in words is "three hundred ninety-seven million, nine hundred ninety-three thousand, eight hundred eleven".