21293772 has 48 divisors (see below), whose sum is σ = 52631040. Its totient is φ = 6689088.

The previous prime is 21293761. The next prime is 21293777. The reversal of 21293772 is 27739212.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21293777) 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, 14253 + ... + 15675.

It is an arithmetic number, because the mean of its divisors is an integer number (1096480).

Almost surely, 2^21293772 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 21293772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26315520).

21293772 is an abundant number, since it is smaller than the sum of its proper divisors (31337268).

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

21293772 is a wasteful number, since it uses less digits than its factorization.

21293772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502 (or 1500 counting only the distinct ones).

The product of its digits is 10584, while the sum is 33.

The square root of 21293772 is about 4614.5175262426. The cubic root of 21293772 is about 277.1729643033.

The spelling of 21293772 in words is "twenty-one million, two hundred ninety-three thousand, seven hundred seventy-two".