811888129 has 4 divisors (see below), whose sum is σ = 874341076. Its totient is φ = 749435184.

The previous prime is 811888081. The next prime is 811888169. The reversal of 811888129 is 921888118.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 535829904 + 276058225 = 23148^2 + 16615^2 .

It is a cyclic number.

It is not a de Polignac number, because 811888129 - 2⁷ = 811888001 is a prime.

It is a super-2 number, since 2×811888129² = 1318324668022241282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811888169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31226454 + ... + 31226479.

It is an arithmetic number, because the mean of its divisors is an integer number (218585269).

Almost surely, 2^811888129 is an apocalyptic number.

It is an amenable number.

811888129 is a deficient number, since it is larger than the sum of its proper divisors (62452947).

811888129 is a wasteful number, since it uses less digits than its factorization.

811888129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62452946.

The product of its digits is 73728, while the sum is 46.

The square root of 811888129 is about 28493.6506787038. The cubic root of 811888129 is about 932.8934929103.

The spelling of 811888129 in words is "eight hundred eleven million, eight hundred eighty-eight thousand, one hundred twenty-nine".