21682853 has 4 divisors (see below), whose sum is σ = 21841260. Its totient is φ = 21524448.

The previous prime is 21682849. The next prime is 21682861. The reversal of 21682853 is 35828612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11035684 + 10647169 = 3322^2 + 3263^2 .

It is a cyclic number.

It is not a de Polignac number, because 21682853 - 2² = 21682849 is a prime.

It is a super-2 number, since 2×21682853² = 940292228439218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21682823) 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, 78998 + ... + 79271.

It is an arithmetic number, because the mean of its divisors is an integer number (5460315).

Almost surely, 2^21682853 is an apocalyptic number.

It is an amenable number.

21682853 is a deficient number, since it is larger than the sum of its proper divisors (158407).

21682853 is a wasteful number, since it uses less digits than its factorization.

21682853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158406.

The product of its digits is 23040, while the sum is 35.

The square root of 21682853 is about 4656.4850477587. The cubic root of 21682853 is about 278.8509586240.

The spelling of 21682853 in words is "twenty-one million, six hundred eighty-two thousand, eight hundred fifty-three".