18229839421 has 4 divisors (see below), whose sum is σ = 18230621500. Its totient is φ = 18229057344.

The previous prime is 18229839413. The next prime is 18229839479. The reversal of 18229839421 is 12493892281.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4828304196 + 13401535225 = 69486^2 + 115765^2 .

It is a cyclic number.

It is not a de Polignac number, because 18229839421 - 2³ = 18229839413 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 (18229839521) 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, 354966 + ... + 403063.

It is an arithmetic number, because the mean of its divisors is an integer number (4557655375).

Almost surely, 2^18229839421 is an apocalyptic number.

It is an amenable number.

18229839421 is a deficient number, since it is larger than the sum of its proper divisors (782079).

18229839421 is an equidigital number, since it uses as much as digits as its factorization.

18229839421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782078.

The product of its digits is 497664, while the sum is 49.

The spelling of 18229839421 in words is "eighteen billion, two hundred twenty-nine million, eight hundred thirty-nine thousand, four hundred twenty-one".