18968721 has 8 divisors (see below), whose sum is σ = 26391360. Its totient is φ = 12095952.

The previous prime is 18968701. The next prime is 18968749. The reversal of 18968721 is 12786981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18968721 - 2⁶ = 18968657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18968701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137386 + ... + 137523.

It is an arithmetic number, because the mean of its divisors is an integer number (3298920).

Almost surely, 2^18968721 is an apocalyptic number.

It is an amenable number.

18968721 is a deficient number, since it is larger than the sum of its proper divisors (7422639).

18968721 is a wasteful number, since it uses less digits than its factorization.

18968721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274935.

The product of its digits is 48384, while the sum is 42.

The square root of 18968721 is about 4355.3095182777. The cubic root of 18968721 is about 266.6936547339.

The spelling of 18968721 in words is "eighteen million, nine hundred sixty-eight thousand, seven hundred twenty-one".