18169323977401 has 3 divisors (see below), whose sum is σ = 18169328239951. Its totient is φ = 18169319714852.

The previous prime is 18169323977323. The next prime is 18169323977411. The reversal of 18169323977401 is 10477932396181.

The square root of 18169323977401 is 4262549.

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., 2691236969001 + 15478087008400 = 1640499^2 + 3934220^2 .

It is not a de Polignac number, because 18169323977401 - 2¹⁷ = 18169323846329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18169323977401.

It is not an unprimeable number, because it can be changed into a prime (18169323977411) 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, 2131275 + ... + 6393823.

Almost surely, 2^{18169323977401} is an apocalyptic number.

18169323977401 is the 4262549-th square number.

18169323977401 is the 2131275-th centered octagonal number.

It is an amenable number.

18169323977401 is a deficient number, since it is larger than the sum of its proper divisors (4262550).

18169323977401 is an frugal number, since it uses more digits than its factorization.

18169323977401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8525098 (or 4262549 counting only the distinct ones).

The product of its (nonzero) digits is 13716864, while the sum is 61.

The spelling of 18169323977401 in words is "eighteen trillion, one hundred sixty-nine billion, three hundred twenty-three million, nine hundred seventy-seven thousand, four hundred one".