21753493 has 8 divisors (see below), whose sum is σ = 22619520. Its totient is φ = 20903520.

The previous prime is 21753419. The next prime is 21753533. The reversal of 21753493 is 39435712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21753493 - 2¹³ = 21745301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21753293) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1213 + ... + 6706.

It is an arithmetic number, because the mean of its divisors is an integer number (2827440).

Almost surely, 2^21753493 is an apocalyptic number.

It is an amenable number.

21753493 is a deficient number, since it is larger than the sum of its proper divisors (866027).

21753493 is an equidigital number, since it uses as much as digits as its factorization.

21753493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8027.

The product of its digits is 22680, while the sum is 34.

The square root of 21753493 is about 4664.0640004185. The cubic root of 21753493 is about 279.1534507840.

The spelling of 21753493 in words is "twenty-one million, seven hundred fifty-three thousand, four hundred ninety-three".