815931401 has 2 divisors, whose sum is σ = 815931402. Its totient is φ = 815931400.

The previous prime is 815931379. The next prime is 815931419. The reversal of 815931401 is 104139518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 782880400 + 33051001 = 27980^2 + 5749^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-815931401 is a prime.

It is a super-2 number, since 2×815931401² = 1331488102275645602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (815931481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407965700 + 407965701.

It is an arithmetic number, because the mean of its divisors is an integer number (407965701).

Almost surely, 2^815931401 is an apocalyptic number.

It is an amenable number.

815931401 is a deficient number, since it is larger than the sum of its proper divisors (1).

815931401 is an equidigital number, since it uses as much as digits as its factorization.

815931401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 815931401 is about 28564.5129662664. The cubic root of 815931401 is about 934.4395589014.

The spelling of 815931401 in words is "eight hundred fifteen million, nine hundred thirty-one thousand, four hundred one".