21135910 has 16 divisors (see below), whose sum is σ = 38973312. Its totient is φ = 8248000.

The previous prime is 21135901. The next prime is 21135911. The reversal of 21135910 is 1953112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21135911) 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, 25366 + ... + 26185.

It is an arithmetic number, because the mean of its divisors is an integer number (2435832).

Almost surely, 2^21135910 is an apocalyptic number.

21135910 is a deficient number, since it is larger than the sum of its proper divisors (17837402).

21135910 is a wasteful number, since it uses less digits than its factorization.

21135910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51599.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 21135910 is about 4597.3807760506. The cubic root of 21135910 is about 276.4863213958.

The spelling of 21135910 in words is "twenty-one million, one hundred thirty-five thousand, nine hundred ten".