21089432 has 64 divisors (see below), whose sum is σ = 49593600. Its totient is φ = 8184960.

The previous prime is 21089407. The next prime is 21089437. The reversal of 21089432 is 23498012.

It is a junction number, because it is equal to n+sod(n) for n = 21089395 and 21089404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089437) 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, 42707 + ... + 43197.

It is an arithmetic number, because the mean of its divisors is an integer number (774900).

Almost surely, 2^21089432 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 21089432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24796800).

21089432 is an abundant number, since it is smaller than the sum of its proper divisors (28504168).

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

21089432 is a wasteful number, since it uses less digits than its factorization.

21089432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576 (or 572 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21089432 is about 4592.3231593606. The cubic root of 21089432 is about 276.2835076027.

The spelling of 21089432 in words is "twenty-one million, eighty-nine thousand, four hundred thirty-two".