21598816 has 24 divisors (see below), whose sum is σ = 43896384. Its totient is φ = 10450560.

The previous prime is 21598807. The next prime is 21598849. The reversal of 21598816 is 61889512.

It is a congruent number.

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, 9895 + ... + 11878.

It is an arithmetic number, because the mean of its divisors is an integer number (1829016).

Almost surely, 2^21598816 is an apocalyptic number.

It is an amenable number.

21598816 is an abundant number, since it is smaller than the sum of its proper divisors (22297568).

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

21598816 is a wasteful number, since it uses less digits than its factorization.

21598816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21814 (or 21806 counting only the distinct ones).

The product of its digits is 34560, while the sum is 40.

The square root of 21598816 is about 4647.4526355844. The cubic root of 21598816 is about 278.4902413671.

The spelling of 21598816 in words is "twenty-one million, five hundred ninety-eight thousand, eight hundred sixteen".