21293216 has 48 divisors (see below), whose sum is σ = 50004864. Its totient is φ = 8726784.

The previous prime is 21293191. The next prime is 21293257. The reversal of 21293216 is 61239212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3086 + ... + 7218.

It is an arithmetic number, because the mean of its divisors is an integer number (1041768).

Almost surely, 2^21293216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21293216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25002432).

21293216 is an abundant number, since it is smaller than the sum of its proper divisors (28711648).

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

21293216 is a wasteful number, since it uses less digits than its factorization.

21293216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4173 (or 4165 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

The square root of 21293216 is about 4614.4572811979. The cubic root of 21293216 is about 277.1705518685.

The spelling of 21293216 in words is "twenty-one million, two hundred ninety-three thousand, two hundred sixteen".