21312032 has 24 divisors (see below), whose sum is σ = 47952576. Its totient is φ = 9133632.

The previous prime is 21312023. The next prime is 21312059. The reversal of 21312032 is 23021312.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21311998 and 21312016.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47348 + ... + 47795.

It is an arithmetic number, because the mean of its divisors is an integer number (1998024).

Almost surely, 2^21312032 is an apocalyptic number.

It is an amenable number.

21312032 is an abundant number, since it is smaller than the sum of its proper divisors (26640544).

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

21312032 is an equidigital number, since it uses as much as digits as its factorization.

21312032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95160 (or 95152 counting only the distinct ones).

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

The square root of 21312032 is about 4616.4956406348. The cubic root of 21312032 is about 277.2521695019.

Adding to 21312032 its reverse (23021312), we get a palindrome (44333344).

The spelling of 21312032 in words is "twenty-one million, three hundred twelve thousand, thirty-two".