21573345 has 8 divisors (see below), whose sum is σ = 34517376. Its totient is φ = 11505776.

The previous prime is 21573317. The next prime is 21573353. The reversal of 21573345 is 54337512.

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

It is a cyclic number.

It is not a de Polignac number, because 21573345 - 2⁶ = 21573281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 719097 + ... + 719126.

It is an arithmetic number, because the mean of its divisors is an integer number (4314672).

Almost surely, 2^21573345 is an apocalyptic number.

It is an amenable number.

21573345 is a deficient number, since it is larger than the sum of its proper divisors (12944031).

21573345 is a wasteful number, since it uses less digits than its factorization.

21573345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1438231.

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

The square root of 21573345 is about 4644.7115088022. The cubic root of 21573345 is about 278.3807258712.

The spelling of 21573345 in words is "twenty-one million, five hundred seventy-three thousand, three hundred forty-five".