21786132 has 24 divisors (see below), whose sum is σ = 51408000. Its totient is φ = 7180096.

The previous prime is 21786113. The next prime is 21786133. The reversal of 21786132 is 23168712.

It is a self number, because there is not a number n which added to its sum of digits gives 21786132.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21786133) 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, 9132 + ... + 11267.

It is an arithmetic number, because the mean of its divisors is an integer number (2142000).

Almost surely, 2^21786132 is an apocalyptic number.

It is an amenable number.

21786132 is an abundant number, since it is smaller than the sum of its proper divisors (29621868).

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

21786132 is a wasteful number, since it uses less digits than its factorization.

21786132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20495 (or 20493 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21786132 is about 4667.5616760788. The cubic root of 21786132 is about 279.2929952150.

The spelling of 21786132 in words is "twenty-one million, seven hundred eighty-six thousand, one hundred thirty-two".