21689902 has 16 divisors (see below), whose sum is σ = 35893872. Its totient is φ = 9766080.

The previous prime is 21689893. The next prime is 21689903. The reversal of 21689902 is 20998612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21689903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9108 + ... + 11239.

It is an arithmetic number, because the mean of its divisors is an integer number (2243367).

Almost surely, 2^21689902 is an apocalyptic number.

21689902 is a deficient number, since it is larger than the sum of its proper divisors (14203970).

21689902 is a wasteful number, since it uses less digits than its factorization.

21689902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20403.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 21689902 is about 4657.2418876412. The cubic root of 21689902 is about 278.8811730895.

The spelling of 21689902 in words is "twenty-one million, six hundred eighty-nine thousand, nine hundred two".