21032312 has 64 divisors (see below), whose sum is σ = 47139840. Its totient is φ = 8611200.

The previous prime is 21032309. The next prime is 21032329. The reversal of 21032312 is 21323012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 160487 + ... + 160617.

It is an arithmetic number, because the mean of its divisors is an integer number (736560).

Almost surely, 2^21032312 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 21032312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23569920).

21032312 is an abundant number, since it is smaller than the sum of its proper divisors (26107528).

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

21032312 is a wasteful number, since it uses less digits than its factorization.

21032312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 248 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21032312 is about 4586.0998680796. The cubic root of 21032312 is about 276.0338472807.

Adding to 21032312 its reverse (21323012), we get a palindrome (42355324).

The spelling of 21032312 in words is "twenty-one million, thirty-two thousand, three hundred twelve".