21909022 has 8 divisors (see below), whose sum is σ = 34796736. Its totient is φ = 10310112.

The previous prime is 21908989. The next prime is 21909029. The reversal of 21909022 is 22090912.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21909029) by changing a digit.

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, 322158 + ... + 322225.

It is an arithmetic number, because the mean of its divisors is an integer number (4349592).

Almost surely, 2^21909022 is an apocalyptic number.

21909022 is a deficient number, since it is larger than the sum of its proper divisors (12887714).

21909022 is a wasteful number, since it uses less digits than its factorization.

21909022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644402.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 21909022 is about 4680.7074251656. The cubic root of 21909022 is about 279.8171510279.

Adding to 21909022 its reverse (22090912), we get a palindrome (43999934).

The spelling of 21909022 in words is "twenty-one million, nine hundred nine thousand, twenty-two".