21860516 has 12 divisors (see below), whose sum is σ = 38371788. Its totient is φ = 10897152.

The previous prime is 21860513. The next prime is 21860533. The reversal of 21860516 is 61506812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 11874916 + 9985600 = 3446^2 + 3160^2 .

It is not an unprimeable number, because it can be changed into a prime (21860513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6761 + ... + 9456.

It is an arithmetic number, because the mean of its divisors is an integer number (3197649).

Almost surely, 2^21860516 is an apocalyptic number.

It is an amenable number.

21860516 is a deficient number, since it is larger than the sum of its proper divisors (16511272).

21860516 is a wasteful number, since it uses less digits than its factorization.

21860516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16558 (or 16556 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21860516 is about 4675.5230723417. The cubic root of 21860516 is about 279.6104958323.

The spelling of 21860516 in words is "twenty-one million, eight hundred sixty thousand, five hundred sixteen".