18421818529 has 3 divisors (see below), whose sum is σ = 18421954257. Its totient is φ = 18421682802.

The previous prime is 18421818523. The next prime is 18421818533. The reversal of 18421818529 is 92581812481.

The square root of 18421818529 is 135727.

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 is not a de Polignac number, because 18421818529 - 2²⁹ = 17884947617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18421818523) 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, 67864 + ... + 203590.

It is an arithmetic number, because the mean of its divisors is an integer number (6140651419).

Almost surely, 2^18421818529 is an apocalyptic number.

18421818529 is the 135727-th square number.

18421818529 is the 67864-th centered octagonal number.

It is an amenable number.

18421818529 is a deficient number, since it is larger than the sum of its proper divisors (135728).

18421818529 is an frugal number, since it uses more digits than its factorization.

18421818529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271454 (or 135727 counting only the distinct ones).

The product of its digits is 368640, while the sum is 49.

Multiplying 18421818529 by its sum of digits (49), we get a square (902669107921 = 950089²).

The spelling of 18421818529 in words is "eighteen billion, four hundred twenty-one million, eight hundred eighteen thousand, five hundred twenty-nine".