18486921 has 4 divisors (see below), whose sum is σ = 24649232. Its totient is φ = 12324612.

The previous prime is 18486911. The next prime is 18486929. The reversal of 18486921 is 12968481.

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 not a de Polignac number, because 18486921 - 2⁶ = 18486857 is a prime.

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 18486921.

It is not an unprimeable number, because it can be changed into a prime (18486929) 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, 3081151 + ... + 3081156.

It is an arithmetic number, because the mean of its divisors is an integer number (6162308).

Almost surely, 2^18486921 is an apocalyptic number.

It is an amenable number.

18486921 is a deficient number, since it is larger than the sum of its proper divisors (6162311).

18486921 is an equidigital number, since it uses as much as digits as its factorization.

18486921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6162310.

The product of its digits is 27648, while the sum is 39.

The square root of 18486921 is about 4299.6419618382. The cubic root of 18486921 is about 264.4162825283.

The spelling of 18486921 in words is "eighteen million, four hundred eighty-six thousand, nine hundred twenty-one".