811870021136 has 10 divisors (see below), whose sum is σ = 1572998165982. Its totient is φ = 405935010560.

The previous prime is 811870021129. The next prime is 811870021199. The reversal of 811870021136 is 631120078118.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 757979184400 + 53890836736 = 870620^2 + 232144^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 811870021136.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25370938145 + ... + 25370938176.

Almost surely, 2^811870021136 is an apocalyptic number.

It is an amenable number.

811870021136 is a deficient number, since it is larger than the sum of its proper divisors (761128144846).

811870021136 is a wasteful number, since it uses less digits than its factorization.

811870021136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50741876329 (or 50741876323 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 811870021136 in words is "eight hundred eleven billion, eight hundred seventy million, twenty-one thousand, one hundred thirty-six".