21610689 has 16 divisors (see below), whose sum is σ = 31495680. Its totient is φ = 13121280.

The previous prime is 21610681. The next prime is 21610691. The reversal of 21610689 is 98601612.

It is not a de Polignac number, because 21610689 - 2³ = 21610681 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21610681) 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, 5254 + ... + 8415.

It is an arithmetic number, because the mean of its divisors is an integer number (1968480).

Almost surely, 2^21610689 is an apocalyptic number.

It is an amenable number.

21610689 is a deficient number, since it is larger than the sum of its proper divisors (9884991).

21610689 is a wasteful number, since it uses less digits than its factorization.

21610689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13720.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21610689 is about 4648.7298265225. The cubic root of 21610689 is about 278.5412612772.

The spelling of 21610689 in words is "twenty-one million, six hundred ten thousand, six hundred eighty-nine".