21132712 has 32 divisors (see below), whose sum is σ = 42739200. Its totient is φ = 9763200.

The previous prime is 21132691. The next prime is 21132719. The reversal of 21132712 is 21723112.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 21132712.

It is not an unprimeable number, because it can be changed into a prime (21132719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4537 + ... + 7927.

It is an arithmetic number, because the mean of its divisors is an integer number (1335600).

Almost surely, 2^21132712 is an apocalyptic number.

It is an amenable number.

21132712 is an abundant number, since it is smaller than the sum of its proper divisors (21606488).

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

21132712 is a wasteful number, since it uses less digits than its factorization.

21132712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3457 (or 3453 counting only the distinct ones).

The product of its digits is 168, while the sum is 19.

The square root of 21132712 is about 4597.0329561577. The cubic root of 21132712 is about 276.4723759691.

Adding to 21132712 its reverse (21723112), we get a palindrome (42855824).

It can be divided in two parts, 211 and 32712, that added together give a palindrome (32923).

The spelling of 21132712 in words is "twenty-one million, one hundred thirty-two thousand, seven hundred twelve".