18438993629 has 4 divisors (see below), whose sum is σ = 21073135584. Its totient is φ = 15804851676.

The previous prime is 18438993613. The next prime is 18438993659. The reversal of 18438993629 is 92639983481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18438993629 - 2⁴ = 18438993613 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 (18438993659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1317070967 + ... + 1317070980.

It is an arithmetic number, because the mean of its divisors is an integer number (5268283896).

Almost surely, 2^18438993629 is an apocalyptic number.

It is an amenable number.

18438993629 is a deficient number, since it is larger than the sum of its proper divisors (2634141955).

18438993629 is an equidigital number, since it uses as much as digits as its factorization.

18438993629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2634141954.

The product of its digits is 20155392, while the sum is 62.

The spelling of 18438993629 in words is "eighteen billion, four hundred thirty-eight million, nine hundred ninety-three thousand, six hundred twenty-nine".