21307032 has 48 divisors (see below), whose sum is σ = 58149000. Its totient is φ = 7047936.

The previous prime is 21306997. The next prime is 21307043. The reversal of 21307032 is 23070312.

It is a super-2 number, since 2×21307032² = 907979225298048, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21306996 and 21307014.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8944 + ... + 11072.

Almost surely, 2^21307032 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 21307032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29074500).

21307032 is an abundant number, since it is smaller than the sum of its proper divisors (36841968).

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

21307032 is a wasteful number, since it uses less digits than its factorization.

21307032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2280 (or 2273 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 21307032 is about 4615.9540725618. The cubic root of 21307032 is about 277.2304858309.

Adding to 21307032 its reverse (23070312), we get a palindrome (44377344).

The spelling of 21307032 in words is "twenty-one million, three hundred seven thousand, thirty-two".