21573201 has 16 divisors (see below), whose sum is σ = 31080896. Its totient is φ = 13231296.

The previous prime is 21573191. The next prime is 21573203. The reversal of 21573201 is 10237512.

It is not a de Polignac number, because 21573201 - 2⁷ = 21573073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21573203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13806 + ... + 15288.

It is an arithmetic number, because the mean of its divisors is an integer number (1942556).

Almost surely, 2^21573201 is an apocalyptic number.

It is an amenable number.

21573201 is a deficient number, since it is larger than the sum of its proper divisors (9507695).

21573201 is a wasteful number, since it uses less digits than its factorization.

21573201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1872.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21573201 is about 4644.6960072754. The cubic root of 21573201 is about 278.3801064816.

The spelling of 21573201 in words is "twenty-one million, five hundred seventy-three thousand, two hundred one".