21508996 has 12 divisors (see below), whose sum is σ = 37749852. Its totient is φ = 10723328.

The previous prime is 21508973. The next prime is 21509003. The reversal of 21508996 is 69980512.

It can be written as a sum of positive squares in 2 ways, for example, as 5827396 + 15681600 = 2414^2 + 3960^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6205 + ... + 9028.

It is an arithmetic number, because the mean of its divisors is an integer number (3145821).

Almost surely, 2^21508996 is an apocalyptic number.

It is an amenable number.

21508996 is a deficient number, since it is larger than the sum of its proper divisors (16240856).

21508996 is a wasteful number, since it uses less digits than its factorization.

21508996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15590 (or 15588 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21508996 is about 4637.7792099236. The cubic root of 21508996 is about 278.1036654257.

The spelling of 21508996 in words is "twenty-one million, five hundred eight thousand, nine hundred ninety-six".