18139479 has 16 divisors (see below), whose sum is σ = 25419264. Its totient is φ = 11484000.

The previous prime is 18139463. The next prime is 18139481. The reversal of 18139479 is 97493181.

It is a happy number.

It is not a de Polignac number, because 18139479 - 2⁴ = 18139463 is a prime.

It is a super-3 number, since 3×18139479³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18139479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18139279) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9549 + ... + 11289.

It is an arithmetic number, because the mean of its divisors is an integer number (1588704).

Almost surely, 2^18139479 is an apocalyptic number.

18139479 is a deficient number, since it is larger than the sum of its proper divisors (7279785).

18139479 is a wasteful number, since it uses less digits than its factorization.

18139479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918.

The product of its digits is 54432, while the sum is 42.

The square root of 18139479 is about 4259.0467243269. The cubic root of 18139479 is about 262.7493213973.

The spelling of 18139479 in words is "eighteen million, one hundred thirty-nine thousand, four hundred seventy-nine".