21311432 has 16 divisors (see below), whose sum is σ = 41696640. Its totient is φ = 10192336.

The previous prime is 21311429. The next prime is 21311443. The reversal of 21311432 is 23411312.

It is a self number, because there is not a number n which added to its sum of digits gives 21311432.

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, 57728 + ... + 58095.

It is an arithmetic number, because the mean of its divisors is an integer number (2606040).

Almost surely, 2^21311432 is an apocalyptic number.

It is an amenable number.

21311432 is a deficient number, since it is larger than the sum of its proper divisors (20385208).

21311432 is a wasteful number, since it uses less digits than its factorization.

21311432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115852 (or 115848 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 21311432 is about 4616.4306558206. The cubic root of 21311432 is about 277.2495676404.

Adding to 21311432 its reverse (23411312), we get a palindrome (44722744).

The spelling of 21311432 in words is "twenty-one million, three hundred eleven thousand, four hundred thirty-two".