111775370821 has 6 divisors (see below), whose sum is σ = 118737158930. Its totient is φ = 105200348736.

The previous prime is 111775370801. The next prime is 111775370831. The reversal of 111775370821 is 128073577111.

It can be written as a sum of positive squares in 3 ways, for example, as 51762620196 + 60012750625 = 227514^2 + 244975^2 .

It is not a de Polignac number, because 111775370821 - 2²⁷ = 111641153093 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 (111775370801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 193382706 + ... + 193383283.

Almost surely, 2^111775370821 is an apocalyptic number.

It is an amenable number.

111775370821 is a deficient number, since it is larger than the sum of its proper divisors (6961788109).

111775370821 is an equidigital number, since it uses as much as digits as its factorization.

111775370821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386766023 (or 386766006 counting only the distinct ones).

The product of its (nonzero) digits is 82320, while the sum is 43.

The spelling of 111775370821 in words is "one hundred eleven billion, seven hundred seventy-five million, three hundred seventy thousand, eight hundred twenty-one".