21600921 has 8 divisors (see below), whose sum is σ = 29471200. Its totient is φ = 14065632.

The previous prime is 21600907. The next prime is 21600937. The reversal of 21600921 is 12900612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21600921 - 2⁵ = 21600889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21600961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83596 + ... + 83853.

It is an arithmetic number, because the mean of its divisors is an integer number (3683900).

Almost surely, 2^21600921 is an apocalyptic number.

It is an amenable number.

21600921 is a deficient number, since it is larger than the sum of its proper divisors (7870279).

21600921 is a wasteful number, since it uses less digits than its factorization.

21600921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167495.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 21600921 is about 4647.6790982167. The cubic root of 21600921 is about 278.4992882043.

The spelling of 21600921 in words is "twenty-one million, six hundred thousand, nine hundred twenty-one".