18172379949 has 4 divisors (see below), whose sum is σ = 24229839936. Its totient is φ = 12114919964.

The previous prime is 18172379821. The next prime is 18172379963. The reversal of 18172379949 is 94997327181.

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 18172379949 - 2⁷ = 18172379821 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18172379892 and 18172379901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18172379999) 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, 3028729989 + ... + 3028729994.

It is an arithmetic number, because the mean of its divisors is an integer number (6057459984).

Almost surely, 2^18172379949 is an apocalyptic number.

It is an amenable number.

18172379949 is a deficient number, since it is larger than the sum of its proper divisors (6057459987).

18172379949 is an equidigital number, since it uses as much as digits as its factorization.

18172379949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6057459986.

The product of its digits is 6858432, while the sum is 60.

The spelling of 18172379949 in words is "eighteen billion, one hundred seventy-two million, three hundred seventy-nine thousand, nine hundred forty-nine".