811628765 has 4 divisors (see below), whose sum is σ = 973954524. Its totient is φ = 649303008.

The previous prime is 811628749. The next prime is 811628767. The reversal of 811628765 is 567826118.

It is a happy number.

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 261210244 + 550418521 = 16162^2 + 23461^2 .

It is a cyclic number.

It is not a de Polignac number, because 811628765 - 2⁴ = 811628749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811628767) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81162872 + ... + 81162881.

It is an arithmetic number, because the mean of its divisors is an integer number (243488631).

Almost surely, 2^811628765 is an apocalyptic number.

It is an amenable number.

811628765 is a deficient number, since it is larger than the sum of its proper divisors (162325759).

811628765 is a wasteful number, since it uses less digits than its factorization.

811628765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162325758.

The product of its digits is 161280, while the sum is 44.

The square root of 811628765 is about 28489.0990556037. The cubic root of 811628765 is about 932.7941422941.

The spelling of 811628765 in words is "eight hundred eleven million, six hundred twenty-eight thousand, seven hundred sixty-five".