18921244 has 6 divisors (see below), whose sum is σ = 33112184. Its totient is φ = 9460620.

The previous prime is 18921233. The next prime is 18921251. The reversal of 18921244 is 44212981.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2365152 + ... + 2365159.

Almost surely, 2^18921244 is an apocalyptic number.

It is an amenable number.

18921244 is a deficient number, since it is larger than the sum of its proper divisors (14190940).

18921244 is a wasteful number, since it uses less digits than its factorization.

18921244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4730315 (or 4730313 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 18921244 is about 4349.8556297882. The cubic root of 18921244 is about 266.4709654418.

It can be divided in two parts, 1892 and 1244, that added together give a square (3136 = 56²).

The spelling of 18921244 in words is "eighteen million, nine hundred twenty-one thousand, two hundred forty-four".