21648099 has 16 divisors (see below), whose sum is σ = 31578624. Its totient is φ = 13082400.

The previous prime is 21648079. The next prime is 21648127. The reversal of 21648099 is 99084612.

It is not a de Polignac number, because 21648099 - 2¹² = 21644003 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21648079) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14502 + ... + 15924.

It is an arithmetic number, because the mean of its divisors is an integer number (1973664).

Almost surely, 2^21648099 is an apocalyptic number.

21648099 is a deficient number, since it is larger than the sum of its proper divisors (9930525).

21648099 is a wasteful number, since it uses less digits than its factorization.

21648099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1898.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21648099 is about 4652.7517664281. The cubic root of 21648099 is about 278.7018950818.

The spelling of 21648099 in words is "twenty-one million, six hundred forty-eight thousand, ninety-nine".