21852723 has 4 divisors (see below), whose sum is σ = 29136968. Its totient is φ = 14568480.

The previous prime is 21852683. The next prime is 21852749. The reversal of 21852723 is 32725812.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21852723 - 2⁶ = 21852659 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21852773) 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 3 ways as a sum of consecutive naturals, for example, 3642118 + ... + 3642123.

It is an arithmetic number, because the mean of its divisors is an integer number (7284242).

Almost surely, 2^21852723 is an apocalyptic number.

21852723 is a deficient number, since it is larger than the sum of its proper divisors (7284245).

21852723 is an equidigital number, since it uses as much as digits as its factorization.

21852723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7284244.

The product of its digits is 6720, while the sum is 30.

The square root of 21852723 is about 4674.6896153649. The cubic root of 21852723 is about 279.5772660041.

The spelling of 21852723 in words is "twenty-one million, eight hundred fifty-two thousand, seven hundred twenty-three".