21648908 has 6 divisors (see below), whose sum is σ = 37885596. Its totient is φ = 10824452.

The previous prime is 21648901. The next prime is 21648931. The reversal of 21648908 is 80984612.

It is not an unprimeable number, because it can be changed into a prime (21648901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2706110 + ... + 2706117.

It is an arithmetic number, because the mean of its divisors is an integer number (6314266).

Almost surely, 2^21648908 is an apocalyptic number.

It is an amenable number.

21648908 is a deficient number, since it is larger than the sum of its proper divisors (16236688).

21648908 is a wasteful number, since it uses less digits than its factorization.

21648908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5412231 (or 5412229 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21648908 is about 4652.8387034154. The cubic root of 21648908 is about 278.7053667804.

The spelling of 21648908 in words is "twenty-one million, six hundred forty-eight thousand, nine hundred eight".