20655287 has 4 divisors (see below), whose sum is σ = 21213576. Its totient is φ = 20097000.

The previous prime is 20655263. The next prime is 20655293. The reversal of 20655287 is 78255602.

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

It is a cyclic number.

It is not a de Polignac number, because 20655287 - 2¹⁸ = 20393143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20655227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 279089 + ... + 279162.

It is an arithmetic number, because the mean of its divisors is an integer number (5303394).

Almost surely, 2^20655287 is an apocalyptic number.

20655287 is a deficient number, since it is larger than the sum of its proper divisors (558289).

20655287 is an equidigital number, since it uses as much as digits as its factorization.

20655287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558288.

The product of its (nonzero) digits is 33600, while the sum is 35.

The square root of 20655287 is about 4544.8087968582. The cubic root of 20655287 is about 274.3744990072.

The spelling of 20655287 in words is "twenty million, six hundred fifty-five thousand, two hundred eighty-seven".