21516522 has 8 divisors (see below), whose sum is σ = 43033056. Its totient is φ = 7172172.

The previous prime is 21516487. The next prime is 21516527. The reversal of 21516522 is 22561512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

21516522 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21516492 and 21516501.

It is not an unprimeable number, because it can be changed into a prime (21516527) 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, 1793038 + ... + 1793049.

It is an arithmetic number, because the mean of its divisors is an integer number (5379132).

Almost surely, 2^21516522 is an apocalyptic number.

21516522 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21516522 is a wasteful number, since it uses less digits than its factorization.

21516522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3586092.

The product of its digits is 1200, while the sum is 24.

The square root of 21516522 is about 4638.5905186813. The cubic root of 21516522 is about 278.1360978108.

The spelling of 21516522 in words is "twenty-one million, five hundred sixteen thousand, five hundred twenty-two".