21210910 has 16 divisors (see below), whose sum is σ = 43634016. Its totient is φ = 7272288.

The previous prime is 21210907. The next prime is 21210929. The reversal of 21210910 is 1901212.

It is a congruent number.

It is an unprimeable number.

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, 151437 + ... + 151576.

It is an arithmetic number, because the mean of its divisors is an integer number (2727126).

Almost surely, 2^21210910 is an apocalyptic number.

21210910 is an abundant number, since it is smaller than the sum of its proper divisors (22423106).

21210910 is a wasteful number, since it uses less digits than its factorization.

21210910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303027.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 21210910 is about 4605.5303711950. The cubic root of 21210910 is about 276.8129691847.

The spelling of 21210910 in words is "twenty-one million, two hundred ten thousand, nine hundred ten".