21944618 has 8 divisors (see below), whose sum is σ = 33084612. Its totient is φ = 10916416.

The previous prime is 21944581. The next prime is 21944651. The reversal of 21944618 is 81644912.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12623809 + 9320809 = 3553^2 + 3053^2 .

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

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 in 3 ways as a sum of consecutive naturals, for example, 27455 + ... + 28242.

Almost surely, 2^21944618 is an apocalyptic number.

21944618 is a deficient number, since it is larger than the sum of its proper divisors (11139994).

21944618 is a wasteful number, since it uses less digits than its factorization.

21944618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55896.

The product of its digits is 13824, while the sum is 35.

The square root of 21944618 is about 4684.5082986371. The cubic root of 21944618 is about 279.9686104268.

The spelling of 21944618 in words is "twenty-one million, nine hundred forty-four thousand, six hundred eighteen".