811125821 has 8 divisors (see below), whose sum is σ = 885787488. Its totient is φ = 736618000.

The previous prime is 811125817. The next prime is 811125823. The reversal of 811125821 is 128521118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 811125821 - 2² = 811125817 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 (811125823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27290 + ... + 48651.

It is an arithmetic number, because the mean of its divisors is an integer number (110723436).

Almost surely, 2^811125821 is an apocalyptic number.

It is an amenable number.

811125821 is a deficient number, since it is larger than the sum of its proper divisors (74661667).

811125821 is a wasteful number, since it uses less digits than its factorization.

811125821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76923.

The product of its digits is 1280, while the sum is 29.

The square root of 811125821 is about 28480.2707325615. The cubic root of 811125821 is about 932.6014268657.

Adding to 811125821 its reverse (128521118), we get a palindrome (939646939).

The spelling of 811125821 in words is "eight hundred eleven million, one hundred twenty-five thousand, eight hundred twenty-one".