21992516 has 48 divisors (see below), whose sum is σ = 48921600. Its totient is φ = 8415360.

The previous prime is 21992501. The next prime is 21992521. The reversal of 21992516 is 61529912.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10310 + ... + 12258.

It is an arithmetic number, because the mean of its divisors is an integer number (1019200).

Almost surely, 2^21992516 is an apocalyptic number.

21992516 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21992516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24460800).

21992516 is an abundant number, since it is smaller than the sum of its proper divisors (26929084).

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

21992516 is a wasteful number, since it uses less digits than its factorization.

21992516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004 (or 2002 counting only the distinct ones).

The product of its digits is 9720, while the sum is 35.

The square root of 21992516 is about 4689.6178948823. The cubic root of 21992516 is about 280.1721560341.

The spelling of 21992516 in words is "twenty-one million, nine hundred ninety-two thousand, five hundred sixteen".