21089510 has 24 divisors (see below), whose sum is σ = 41109120. Its totient is φ = 7786272.

The previous prime is 21089501. The next prime is 21089521. The reversal of 21089510 is 1598012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 21089510.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4550 + ... + 7929.

It is an arithmetic number, because the mean of its divisors is an integer number (1712880).

Almost surely, 2^21089510 is an apocalyptic number.

21089510 is a deficient number, since it is larger than the sum of its proper divisors (20019610).

21089510 is a wasteful number, since it uses less digits than its factorization.

21089510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12512 (or 12499 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 21089510 is about 4592.3316517865. The cubic root of 21089510 is about 276.2838482170.

The spelling of 21089510 in words is "twenty-one million, eighty-nine thousand, five hundred ten".