397805761 has 2 divisors, whose sum is σ = 397805762. Its totient is φ = 397805760.

The previous prime is 397805743. The next prime is 397805767. The reversal of 397805761 is 167508793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 289000000 + 108805761 = 17000^2 + 10431^2 .

It is a cyclic number.

It is not a de Polignac number, because 397805761 - 2²³ = 389417153 is a prime.

It is not a weakly prime, because it can be changed into another prime (397805767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198902880 + 198902881.

It is an arithmetic number, because the mean of its divisors is an integer number (198902881).

Almost surely, 2^397805761 is an apocalyptic number.

It is an amenable number.

397805761 is a deficient number, since it is larger than the sum of its proper divisors (1).

397805761 is an equidigital number, since it uses as much as digits as its factorization.

397805761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 317520, while the sum is 46.

The square root of 397805761 is about 19945.0685885008. The cubic root of 397805761 is about 735.4565543927.

The spelling of 397805761 in words is "three hundred ninety-seven million, eight hundred five thousand, seven hundred sixty-one".