21316032 has 84 divisors (see below), whose sum is σ = 63794640. Its totient is φ = 6792192.

The previous prime is 21316027. The next prime is 21316037. The reversal of 21316032 is 23061312.

It is an interprime number because it is at equal distance from previous prime (21316027) and next prime (21316037).

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

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 21315996 and 21316014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21316037) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12444 + ... + 14052.

It is an arithmetic number, because the mean of its divisors is an integer number (759460).

Almost surely, 2^21316032 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 21316032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31897320).

21316032 is an abundant number, since it is smaller than the sum of its proper divisors (42478608).

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

21316032 is a wasteful number, since it uses less digits than its factorization.

21316032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1650 (or 1637 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 21316032 is about 4616.9288493543. The cubic root of 21316032 is about 277.2695139969.

Adding to 21316032 its reverse (23061312), we get a palindrome (44377344).

The spelling of 21316032 in words is "twenty-one million, three hundred sixteen thousand, thirty-two".