21239088 has 80 divisors (see below), whose sum is σ = 59850336. Its totient is φ = 6451200.

The previous prime is 21239087. The next prime is 21239173. The reversal of 21239088 is 88093212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21239081) 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, 62856 + ... + 63192.

Almost surely, 2^21239088 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 21239088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29925168).

21239088 is an abundant number, since it is smaller than the sum of its proper divisors (38611248).

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

21239088 is a wasteful number, since it uses less digits than its factorization.

21239088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 21239088 is about 4608.5885040867. The cubic root of 21239088 is about 276.9354939352.

It can be divided in two parts, 2123 and 9088, that added together give a palindrome (11211).

The spelling of 21239088 in words is "twenty-one million, two hundred thirty-nine thousand, eighty-eight".