21243292 has 48 divisors (see below), whose sum is σ = 45418240. Its totient is φ = 8491392.

The previous prime is 21243263. The next prime is 21243293. The reversal of 21243292 is 29234212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243293) 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, 38563 + ... + 39109.

Almost surely, 2^21243292 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 21243292, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22709120).

21243292 is an abundant number, since it is smaller than the sum of its proper divisors (24174948).

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

21243292 is a wasteful number, since it uses less digits than its factorization.

21243292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650 (or 648 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 21243292 is about 4609.0445864626. The cubic root of 21243292 is about 276.9537646508.

The spelling of 21243292 in words is "twenty-one million, two hundred forty-three thousand, two hundred ninety-two".