21534753 has 4 divisors (see below), whose sum is σ = 28713008. Its totient is φ = 14356500.

The previous prime is 21534743. The next prime is 21534757. The reversal of 21534753 is 35743512.

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 not a de Polignac number, because 21534753 - 2⁹ = 21534241 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 21534753.

It is not an unprimeable number, because it can be changed into a prime (21534757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3589123 + ... + 3589128.

It is an arithmetic number, because the mean of its divisors is an integer number (7178252).

Almost surely, 2^21534753 is an apocalyptic number.

It is an amenable number.

21534753 is a deficient number, since it is larger than the sum of its proper divisors (7178255).

21534753 is an equidigital number, since it uses as much as digits as its factorization.

21534753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7178254.

The product of its digits is 12600, while the sum is 30.

The square root of 21534753 is about 4640.5552469505. Note that the first 3 decimals coincide. The cubic root of 21534753 is about 278.2146307591.

The spelling of 21534753 in words is "twenty-one million, five hundred thirty-four thousand, seven hundred fifty-three".