811591601 has 2 divisors, whose sum is σ = 811591602. Its totient is φ = 811591600.

The previous prime is 811591567. The next prime is 811591657. The reversal of 811591601 is 106195118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 770118001 + 41473600 = 27751^2 + 6440^2 .

It is a cyclic number.

It is not a de Polignac number, because 811591601 - 2¹⁸ = 811329457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (811591681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405795800 + 405795801.

It is an arithmetic number, because the mean of its divisors is an integer number (405795801).

Almost surely, 2^811591601 is an apocalyptic number.

It is an amenable number.

811591601 is a deficient number, since it is larger than the sum of its proper divisors (1).

811591601 is an equidigital number, since it uses as much as digits as its factorization.

811591601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 32.

The square root of 811591601 is about 28488.4467986586. The cubic root of 811591601 is about 932.7799047132.

The spelling of 811591601 in words is "eight hundred eleven million, five hundred ninety-one thousand, six hundred one".