21067573 has 4 divisors (see below), whose sum is σ = 22306860. Its totient is φ = 19828288.

The previous prime is 21067567. The next prime is 21067577. The reversal of 21067573 is 37576012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8514724 + 12552849 = 2918^2 + 3543^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21067573 is a prime.

It is a super-2 number, since 2×21067573² = 887685264220658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21067577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 619618 + ... + 619651.

It is an arithmetic number, because the mean of its divisors is an integer number (5576715).

Almost surely, 2^21067573 is an apocalyptic number.

It is an amenable number.

21067573 is a deficient number, since it is larger than the sum of its proper divisors (1239287).

21067573 is a wasteful number, since it uses less digits than its factorization.

21067573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1239286.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 21067573 is about 4589.9425922336. The cubic root of 21067573 is about 276.1880195094.

The spelling of 21067573 in words is "twenty-one million, sixty-seven thousand, five hundred seventy-three".