21229573 has 4 divisors (see below), whose sum is σ = 21723328. Its totient is φ = 20735820.

The previous prime is 21229501. The next prime is 21229577. The reversal of 21229573 is 37592212.

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 21229573 - 2¹³ = 21221381 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21229577) 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, 246813 + ... + 246898.

It is an arithmetic number, because the mean of its divisors is an integer number (5430832).

Almost surely, 2^21229573 is an apocalyptic number.

It is an amenable number.

21229573 is a deficient number, since it is larger than the sum of its proper divisors (493755).

21229573 is an equidigital number, since it uses as much as digits as its factorization.

21229573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493754.

The product of its digits is 7560, while the sum is 31.

The square root of 21229573 is about 4607.5560767070. The cubic root of 21229573 is about 276.8941325418.

The spelling of 21229573 in words is "twenty-one million, two hundred twenty-nine thousand, five hundred seventy-three".