18644372 has 6 divisors (see below), whose sum is σ = 32627658. Its totient is φ = 9322184.

The previous prime is 18644363. The next prime is 18644441. The reversal of 18644372 is 27344681.

It can be written as a sum of positive squares in only one way, i.e., 18369796 + 274576 = 4286^2 + 524^2 .

It is a super-2 number, since 2×18644372² = 695225214548768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2330543 + ... + 2330550.

It is an arithmetic number, because the mean of its divisors is an integer number (5437943).

Almost surely, 2^18644372 is an apocalyptic number.

It is an amenable number.

18644372 is a deficient number, since it is larger than the sum of its proper divisors (13983286).

18644372 is a wasteful number, since it uses less digits than its factorization.

18644372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4661097 (or 4661095 counting only the distinct ones).

The product of its digits is 32256, while the sum is 35.

The square root of 18644372 is about 4317.9129217714. The cubic root of 18644372 is about 265.1648292224.

The spelling of 18644372 in words is "eighteen million, six hundred forty-four thousand, three hundred seventy-two".