18308822612161 has 3 divisors (see below), whose sum is σ = 18308826891043. Its totient is φ = 18308818333280.

The previous prime is 18308822612149. The next prime is 18308822612183. The reversal of 18308822612161 is 16121622880381.

The square root of 18308822612161 is 4278881.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 807987052161 + 17500835560000 = 898881^2 + 4183400^2 .

It is not a de Polignac number, because 18308822612161 - 2¹³ = 18308822603969 is a prime.

It is a super-3 number, since 3×18308822612161³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18308822612141) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2139441 + ... + 6418321.

Almost surely, 2^{18308822612161} is an apocalyptic number.

18308822612161 is the 4278881-st square number.

18308822612161 is the 2139441-st centered octagonal number.

It is an amenable number.

18308822612161 is a deficient number, since it is larger than the sum of its proper divisors (4278882).

18308822612161 is an frugal number, since it uses more digits than its factorization.

18308822612161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8557762 (or 4278881 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 49.

Multiplying 18308822612161 by its sum of digits (49), we get a square (897132307995889 = 29952167²).

The spelling of 18308822612161 in words is "eighteen trillion, three hundred eight billion, eight hundred twenty-two million, six hundred twelve thousand, one hundred sixty-one".