21290910 has 32 divisors (see below), whose sum is σ = 52481952. Its totient is φ = 5523840.

The previous prime is 21290903. The next prime is 21290921. The reversal of 21290910 is 1909212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8481 + ... + 10700.

It is an arithmetic number, because the mean of its divisors is an integer number (1640061).

Almost surely, 2^21290910 is an apocalyptic number.

21290910 is an abundant number, since it is smaller than the sum of its proper divisors (31191042).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21290910 is a wasteful number, since it uses less digits than its factorization.

21290910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19228.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 21290910 is about 4614.2074075620. The cubic root of 21290910 is about 277.1605458903.

The spelling of 21290910 in words is "twenty-one million, two hundred ninety thousand, nine hundred ten".