21524493 has 8 divisors (see below), whose sum is σ = 28720768. Its totient is φ = 14338944.

The previous prime is 21524483. The next prime is 21524501. The reversal of 21524493 is 39442512.

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

It is not a de Polignac number, because 21524493 - 2⁶ = 21524429 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21524493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21524423) 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, 6396 + ... + 9162.

It is an arithmetic number, because the mean of its divisors is an integer number (3590096).

Almost surely, 2^21524493 is an apocalyptic number.

It is an amenable number.

21524493 is a deficient number, since it is larger than the sum of its proper divisors (7196275).

21524493 is a wasteful number, since it uses less digits than its factorization.

21524493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5363.

The product of its digits is 8640, while the sum is 30.

The square root of 21524493 is about 4639.4496440850. The cubic root of 21524493 is about 278.1704396237.

The spelling of 21524493 in words is "twenty-one million, five hundred twenty-four thousand, four hundred ninety-three".