21766465 has 16 divisors (see below), whose sum is σ = 29935872. Its totient is φ = 14883264.

The previous prime is 21766439. The next prime is 21766513. The reversal of 21766465 is 56466712.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21766465 is a prime.

It is a Duffinian 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, 16407 + ... + 17683.

It is an arithmetic number, because the mean of its divisors is an integer number (1870992).

Almost surely, 2^21766465 is an apocalyptic number.

It is an amenable number.

21766465 is a deficient number, since it is larger than the sum of its proper divisors (8169407).

21766465 is a wasteful number, since it uses less digits than its factorization.

21766465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1776.

The product of its digits is 60480, while the sum is 37.

The square root of 21766465 is about 4665.4544258839. The cubic root of 21766465 is about 279.2089278363.

The spelling of 21766465 in words is "twenty-one million, seven hundred sixty-six thousand, four hundred sixty-five".