20897585 has 4 divisors (see below), whose sum is σ = 25077108. Its totient is φ = 16718064.

The previous prime is 20897579. The next prime is 20897599. The reversal of 20897585 is 58579802.

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 8898289 + 11999296 = 2983^2 + 3464^2 .

It is a cyclic number.

It is not a de Polignac number, because 20897585 - 2¹² = 20893489 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2089754 + ... + 2089763.

It is an arithmetic number, because the mean of its divisors is an integer number (6269277).

Almost surely, 2^20897585 is an apocalyptic number.

It is an amenable number.

20897585 is a deficient number, since it is larger than the sum of its proper divisors (4179523).

20897585 is an equidigital number, since it uses as much as digits as its factorization.

20897585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4179522.

The product of its (nonzero) digits is 201600, while the sum is 44.

The square root of 20897585 is about 4571.3876449061. The cubic root of 20897585 is about 275.4431862100.

The spelling of 20897585 in words is "twenty million, eight hundred ninety-seven thousand, five hundred eighty-five".