21732573 has 4 divisors (see below), whose sum is σ = 28976768. Its totient is φ = 14488380.

The previous prime is 21732551. The next prime is 21732577. The reversal of 21732573 is 37523712.

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 21732573 - 2⁸ = 21732317 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 21732573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21732577) 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, 3622093 + ... + 3622098.

It is an arithmetic number, because the mean of its divisors is an integer number (7244192).

Almost surely, 2^21732573 is an apocalyptic number.

It is an amenable number.

21732573 is a deficient number, since it is larger than the sum of its proper divisors (7244195).

21732573 is an equidigital number, since it uses as much as digits as its factorization.

21732573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7244194.

The product of its digits is 8820, while the sum is 30.

The square root of 21732573 is about 4661.8207816260. The cubic root of 21732573 is about 279.0639362213.

The spelling of 21732573 in words is "twenty-one million, seven hundred thirty-two thousand, five hundred seventy-three".