18979131 has 4 divisors (see below), whose sum is σ = 25305512. Its totient is φ = 12652752.

The previous prime is 18979127. The next prime is 18979133. The reversal of 18979131 is 13197981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13197981 = 3 ⋅4399327.

It is not a de Polignac number, because 18979131 - 2² = 18979127 is a prime.

It is a super-3 number, since 3×18979131³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18979131.

It is not an unprimeable number, because it can be changed into a prime (18979133) 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, 3163186 + ... + 3163191.

It is an arithmetic number, because the mean of its divisors is an integer number (6326378).

Almost surely, 2^18979131 is an apocalyptic number.

18979131 is a deficient number, since it is larger than the sum of its proper divisors (6326381).

18979131 is an equidigital number, since it uses as much as digits as its factorization.

18979131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6326380.

The product of its digits is 13608, while the sum is 39.

The square root of 18979131 is about 4356.5044473752. The cubic root of 18979131 is about 266.7424328113.

It can be divided in two parts, 18979 and 131, that added together give a triangular number (19110 = T₁₉₅).

The spelling of 18979131 in words is "eighteen million, nine hundred seventy-nine thousand, one hundred thirty-one".