21159910 has 16 divisors (see below), whose sum is σ = 38227536. Its totient is φ = 8432928.

The previous prime is 21159907. The next prime is 21159911. The reversal of 21159910 is 1995112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21159911) 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, 909 + ... + 6568.

It is an arithmetic number, because the mean of its divisors is an integer number (2389221).

Almost surely, 2^21159910 is an apocalyptic number.

21159910 is a deficient number, since it is larger than the sum of its proper divisors (17067626).

21159910 is a wasteful number, since it uses less digits than its factorization.

21159910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7767.

The product of its (nonzero) digits is 810, while the sum is 28.

The square root of 21159910 is about 4599.9902173809. The cubic root of 21159910 is about 276.5909326424.

The spelling of 21159910 in words is "twenty-one million, one hundred fifty-nine thousand, nine hundred ten".