21323736 has 96 divisors (see below), whose sum is σ = 68490240. Its totient is φ = 6088608.

The previous prime is 21323717. The next prime is 21323747. The reversal of 21323736 is 63732312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12825 + ... + 14391.

It is an arithmetic number, because the mean of its divisors is an integer number (713440).

Almost surely, 2^21323736 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 21323736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34245120).

21323736 is an abundant number, since it is smaller than the sum of its proper divisors (47166504).

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

21323736 is a wasteful number, since it uses less digits than its factorization.

21323736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1595 (or 1579 counting only the distinct ones).

The product of its digits is 4536, while the sum is 27.

The square root of 21323736 is about 4617.7630948328. The cubic root of 21323736 is about 277.3029133815.

The spelling of 21323736 in words is "twenty-one million, three hundred twenty-three thousand, seven hundred thirty-six".