811121872 has 40 divisors (see below), whose sum is σ = 1723371840. Its totient is φ = 366766080.

The previous prime is 811121863. The next prime is 811121873. The reversal of 811121872 is 278121118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811121873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22029 + ... + 45907.

It is an arithmetic number, because the mean of its divisors is an integer number (43084296).

Almost surely, 2^811121872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 811121872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (861685920).

811121872 is an abundant number, since it is smaller than the sum of its proper divisors (912249968).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811121872 is a wasteful number, since it uses less digits than its factorization.

811121872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24091 (or 24085 counting only the distinct ones).

The product of its digits is 1792, while the sum is 31.

The square root of 811121872 is about 28480.2014037822. The cubic root of 811121872 is about 932.5999133935.

The spelling of 811121872 in words is "eight hundred eleven million, one hundred twenty-one thousand, eight hundred seventy-two".