18521444 has 12 divisors (see below), whose sum is σ = 32461884. Its totient is φ = 9246624.

The previous prime is 18521429. The next prime is 18521453. The reversal of 18521444 is 44412581.

It can be written as a sum of positive squares in 2 ways, for example, as 15054400 + 3467044 = 3880^2 + 1862^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227 + ... + 6090.

It is an arithmetic number, because the mean of its divisors is an integer number (2705157).

Almost surely, 2^18521444 is an apocalyptic number.

It is an amenable number.

18521444 is a deficient number, since it is larger than the sum of its proper divisors (13940440).

18521444 is a wasteful number, since it uses less digits than its factorization.

18521444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7054 (or 7052 counting only the distinct ones).

The product of its digits is 5120, while the sum is 29.

The square root of 18521444 is about 4303.6547259277. The cubic root of 18521444 is about 264.5807729983.

The spelling of 18521444 in words is "eighteen million, five hundred twenty-one thousand, four hundred forty-four".