18987479 has 16 divisors (see below), whose sum is σ = 22963200. Its totient is φ = 15336864.

The previous prime is 18987457. The next prime is 18987481. The reversal of 18987479 is 97478981.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18987479 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 18987479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18987499) 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, 48617 + ... + 49005.

It is an arithmetic number, because the mean of its divisors is an integer number (1435200).

Almost surely, 2^18987479 is an apocalyptic number.

18987479 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18987479 is a deficient number, since it is larger than the sum of its proper divisors (3975721).

18987479 is a wasteful number, since it uses less digits than its factorization.

18987479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782.

The product of its digits is 1016064, while the sum is 53.

The square root of 18987479 is about 4357.4624496374. The cubic root of 18987479 is about 266.7815361020.

The spelling of 18987479 in words is "eighteen million, nine hundred eighty-seven thousand, four hundred seventy-nine".