21320292 has 72 divisors (see below), whose sum is σ = 58605120. Its totient is φ = 6014400.

The previous prime is 21320267. The next prime is 21320297. The reversal of 21320292 is 29202312.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21320297) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59209 + ... + 59567.

It is an arithmetic number, because the mean of its divisors is an integer number (813960).

Almost surely, 2^21320292 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 21320292, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29302560).

21320292 is an abundant number, since it is smaller than the sum of its proper divisors (37284828).

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

21320292 is a wasteful number, since it uses less digits than its factorization.

21320292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21320292 is about 4617.3901719478. The cubic root of 21320292 is about 277.2879834984.

It can be divided in two parts, 21320 and 292, that added together give a palindrome (21612).

The spelling of 21320292 in words is "twenty-one million, three hundred twenty thousand, two hundred ninety-two".