21272585 has 16 divisors (see below), whose sum is σ = 26925696. Its totient is φ = 16101888.

The previous prime is 21272579. The next prime is 21272611. The reversal of 21272585 is 58527212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21272585 - 2¹⁸ = 21010441 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10202 + ... + 12108.

It is an arithmetic number, because the mean of its divisors is an integer number (1682856).

Almost surely, 2^21272585 is an apocalyptic number.

It is an amenable number.

21272585 is a deficient number, since it is larger than the sum of its proper divisors (5653111).

21272585 is a wasteful number, since it uses less digits than its factorization.

21272585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032.

The product of its digits is 11200, while the sum is 32.

The square root of 21272585 is about 4612.2212652907. The cubic root of 21272585 is about 277.0810060797.

Adding to 21272585 its reverse (58527212), we get a palindrome (79799797).

The spelling of 21272585 in words is "twenty-one million, two hundred seventy-two thousand, five hundred eighty-five".