21137910 has 32 divisors (see below), whose sum is σ = 50893920. Its totient is φ = 5618688.

The previous prime is 21137891. The next prime is 21137911. The reversal of 21137910 is 1973112.

It is a super-3 number, since 3×21137910³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21137911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10246 + ... + 12134.

It is an arithmetic number, because the mean of its divisors is an integer number (1590435).

Almost surely, 2^21137910 is an apocalyptic number.

21137910 is an abundant number, since it is smaller than the sum of its proper divisors (29756010).

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

21137910 is a wasteful number, since it uses less digits than its factorization.

21137910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2272.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 21137910 is about 4597.5982860620. The cubic root of 21137910 is about 276.4950420234.

The spelling of 21137910 in words is "twenty-one million, one hundred thirty-seven thousand, nine hundred ten".