20898655 has 4 divisors (see below), whose sum is σ = 25078392. Its totient is φ = 16718920.

The previous prime is 20898649. The next prime is 20898667. The reversal of 20898655 is 55689802.

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

It is not a de Polignac number, because 20898655 - 2¹¹ = 20896607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2089861 + ... + 2089870.

It is an arithmetic number, because the mean of its divisors is an integer number (6269598).

Almost surely, 2^20898655 is an apocalyptic number.

20898655 is a deficient number, since it is larger than the sum of its proper divisors (4179737).

20898655 is an equidigital number, since it uses as much as digits as its factorization.

20898655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4179736.

The product of its (nonzero) digits is 172800, while the sum is 43.

The square root of 20898655 is about 4571.5046757058. The cubic root of 20898655 is about 275.4478872186.

The spelling of 20898655 in words is "twenty million, eight hundred ninety-eight thousand, six hundred fifty-five".