21944290 has 8 divisors (see below), whose sum is σ = 39499740. Its totient is φ = 8777712.

The previous prime is 21944269. The next prime is 21944291. The reversal of 21944290 is 9244912.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20349121 + 1595169 = 4511^2 + 1263^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21944291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1097205 + ... + 1097224.

Almost surely, 2^21944290 is an apocalyptic number.

21944290 is a deficient number, since it is larger than the sum of its proper divisors (17555450).

21944290 is a wasteful number, since it uses less digits than its factorization.

21944290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2194436.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21944290 is about 4684.4732894958. The cubic root of 21944290 is about 279.9672155493.

The spelling of 21944290 in words is "twenty-one million, nine hundred forty-four thousand, two hundred ninety".