21782472 has 32 divisors (see below), whose sum is σ = 56825280. Its totient is φ = 6944960.

The previous prime is 21782461. The next prime is 21782473. The reversal of 21782472 is 27428712.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21782473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19179 + ... + 20282.

It is an arithmetic number, because the mean of its divisors is an integer number (1775790).

Almost surely, 2^21782472 is an apocalyptic number.

It is an amenable number.

21782472 is an abundant number, since it is smaller than the sum of its proper divisors (35042808).

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

21782472 is a wasteful number, since it uses less digits than its factorization.

21782472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39493 (or 39489 counting only the distinct ones).

The product of its digits is 12544, while the sum is 33.

The square root of 21782472 is about 4667.1695919476. The cubic root of 21782472 is about 279.2773542312.

The spelling of 21782472 in words is "twenty-one million, seven hundred eighty-two thousand, four hundred seventy-two".