21689110 has 16 divisors (see below), whose sum is σ = 41337216. Its totient is φ = 8165248.

The previous prime is 21689081. The next prime is 21689111. The reversal of 21689110 is 1198612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21689111) 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 7 ways as a sum of consecutive naturals, for example, 63622 + ... + 63961.

It is an arithmetic number, because the mean of its divisors is an integer number (2583576).

Almost surely, 2^21689110 is an apocalyptic number.

21689110 is a deficient number, since it is larger than the sum of its proper divisors (19648106).

21689110 is a wasteful number, since it uses less digits than its factorization.

21689110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127607.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 21689110 is about 4657.1568579982. The cubic root of 21689110 is about 278.8777786285.

The spelling of 21689110 in words is "twenty-one million, six hundred eighty-nine thousand, one hundred ten".