811861399 has 2 divisors, whose sum is σ = 811861400. Its totient is φ = 811861398.

The previous prime is 811861373. The next prime is 811861439. The reversal of 811861399 is 993168118.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 811861399 - 2²⁵ = 778306967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (811868399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405930699 + 405930700.

It is an arithmetic number, because the mean of its divisors is an integer number (405930700).

Almost surely, 2^811861399 is an apocalyptic number.

811861399 is a deficient number, since it is larger than the sum of its proper divisors (1).

811861399 is an equidigital number, since it uses as much as digits as its factorization.

811861399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 46.

The square root of 811861399 is about 28493.1816229778. The cubic root of 811861399 is about 932.8832548345.

The spelling of 811861399 in words is "eight hundred eleven million, eight hundred sixty-one thousand, three hundred ninety-nine".