21782152 has 64 divisors (see below), whose sum is σ = 48988800. Its totient is φ = 8885760.

The previous prime is 21782149. The next prime is 21782153. The reversal of 21782152 is 25128712.

It is a super-2 number, since 2×21782152² = 948924291502208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 21782152.

It is not an unprimeable number, because it can be changed into a prime (21782153) 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 15 ways as a sum of consecutive naturals, for example, 121599 + ... + 121777.

It is an arithmetic number, because the mean of its divisors is an integer number (765450).

Almost surely, 2^21782152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21782152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24494400).

21782152 is an abundant number, since it is smaller than the sum of its proper divisors (27206648).

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

21782152 is a wasteful number, since it uses less digits than its factorization.

21782152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 282 counting only the distinct ones).

The product of its digits is 2240, while the sum is 28.

The square root of 21782152 is about 4667.1353098019. The cubic root of 21782152 is about 279.2759866302.

It can be divided in two parts, 217 and 82152, that added together give a square (82369 = 287²).

The spelling of 21782152 in words is "twenty-one million, seven hundred eighty-two thousand, one hundred fifty-two".