21682753 has 4 divisors (see below), whose sum is σ = 21730048. Its totient is φ = 21635460.

The previous prime is 21682709. The next prime is 21682757. The reversal of 21682753 is 35728612.

It is a happy number.

21682753 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21682753 - 2¹³ = 21674561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21682757) 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 3 ways as a sum of consecutive naturals, for example, 22953 + ... + 23878.

It is an arithmetic number, because the mean of its divisors is an integer number (5432512).

Almost surely, 2^21682753 is an apocalyptic number.

It is an amenable number.

21682753 is a deficient number, since it is larger than the sum of its proper divisors (47295).

21682753 is an equidigital number, since it uses as much as digits as its factorization.

21682753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47294.

The product of its digits is 20160, while the sum is 34.

The square root of 21682753 is about 4656.4743100333. The cubic root of 21682753 is about 278.8505299421.

The spelling of 21682753 in words is "twenty-one million, six hundred eighty-two thousand, seven hundred fifty-three".