21786452 has 12 divisors (see below), whose sum is σ = 40369140. Its totient is φ = 10252416.

The previous prime is 21786449. The next prime is 21786461. The reversal of 21786452 is 25468712.

It can be written as a sum of positive squares in 2 ways, for example, as 18267076 + 3519376 = 4274^2 + 1876^2 .

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 160127 + ... + 160262.

It is an arithmetic number, because the mean of its divisors is an integer number (3364095).

Almost surely, 2^21786452 is an apocalyptic number.

It is an amenable number.

21786452 is a deficient number, since it is larger than the sum of its proper divisors (18582688).

21786452 is a wasteful number, since it uses less digits than its factorization.

21786452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320410 (or 320408 counting only the distinct ones).

The product of its digits is 26880, while the sum is 35.

The square root of 21786452 is about 4667.5959550929. The cubic root of 21786452 is about 279.2943626494.

The spelling of 21786452 in words is "twenty-one million, seven hundred eighty-six thousand, four hundred fifty-two".