18609125821 has 16 divisors (see below), whose sum is σ = 22813015680. Its totient is φ = 14937088320.

The previous prime is 18609125819. The next prime is 18609125851. The reversal of 18609125821 is 12852190681.

It is not a de Polignac number, because 18609125821 - 2¹ = 18609125819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18609125851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2825706 + ... + 2832283.

It is an arithmetic number, because the mean of its divisors is an integer number (1425813480).

Almost surely, 2^18609125821 is an apocalyptic number.

18609125821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18609125821 is a deficient number, since it is larger than the sum of its proper divisors (4203889859).

18609125821 is a wasteful number, since it uses less digits than its factorization.

18609125821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5658036.

The product of its (nonzero) digits is 69120, while the sum is 43.

The spelling of 18609125821 in words is "eighteen billion, six hundred nine million, one hundred twenty-five thousand, eight hundred twenty-one".