18451979 has 24 divisors (see below), whose sum is σ = 23461200. Its totient is φ = 14382144.

The previous prime is 18451949. The next prime is 18451981. The reversal of 18451979 is 97915481.

It is not a de Polignac number, because 18451979 - 2²⁴ = 1674763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18451949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52697 + ... + 53045.

It is an arithmetic number, because the mean of its divisors is an integer number (977550).

Almost surely, 2^18451979 is an apocalyptic number.

18451979 is a deficient number, since it is larger than the sum of its proper divisors (5009221).

18451979 is a wasteful number, since it uses less digits than its factorization.

18451979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 452 counting only the distinct ones).

The product of its digits is 90720, while the sum is 44.

The square root of 18451979 is about 4295.5766783984. The cubic root of 18451979 is about 264.2495870058.

The spelling of 18451979 in words is "eighteen million, four hundred fifty-one thousand, nine hundred seventy-nine".