21909922 has 8 divisors (see below), whose sum is σ = 33006636. Its totient is φ = 10907712.

The previous prime is 21909917. The next prime is 21909941. The reversal of 21909922 is 22990912.

It can be written as a sum of positive squares in 2 ways, for example, as 21446161 + 463761 = 4631^2 + 681^2 .

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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23043 + ... + 23974.

Almost surely, 2^21909922 is an apocalyptic number.

21909922 is a deficient number, since it is larger than the sum of its proper divisors (11096714).

21909922 is a wasteful number, since it uses less digits than its factorization.

21909922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47252.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 21909922 is about 4680.8035634921. The cubic root of 21909922 is about 279.8209825087.

It can be divided in two parts, 2 and 1909922, that added together give a square (1909924 = 1382²).

The spelling of 21909922 in words is "twenty-one million, nine hundred nine thousand, nine hundred twenty-two".