18721066 has 32 divisors (see below), whose sum is σ = 35763840. Its totient is φ = 7148736.

The previous prime is 18721033. The next prime is 18721091. The reversal of 18721066 is 66012781.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3505 + ... + 7051.

It is an arithmetic number, because the mean of its divisors is an integer number (1117620).

Almost surely, 2^18721066 is an apocalyptic number.

18721066 is a deficient number, since it is larger than the sum of its proper divisors (17042774).

18721066 is a wasteful number, since it uses less digits than its factorization.

18721066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3598.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 18721066 is about 4326.7847184717. The cubic root of 18721066 is about 265.5279187743.

The spelling of 18721066 in words is "eighteen million, seven hundred twenty-one thousand, sixty-six".