20855155 has 4 divisors (see below), whose sum is σ = 25026192. Its totient is φ = 16684120.

The previous prime is 20855123. The next prime is 20855201. The reversal of 20855155 is 55155802.

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

It is not a de Polignac number, because 20855155 - 2⁵ = 20855123 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, 2085511 + ... + 2085520.

It is an arithmetic number, because the mean of its divisors is an integer number (6256548).

Almost surely, 2^20855155 is an apocalyptic number.

20855155 is a deficient number, since it is larger than the sum of its proper divisors (4171037).

20855155 is an equidigital number, since it uses as much as digits as its factorization.

20855155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4171036.

The product of its (nonzero) digits is 10000, while the sum is 31.

The square root of 20855155 is about 4566.7444640575. The cubic root of 20855155 is about 275.2566419588.

The spelling of 20855155 in words is "twenty million, eight hundred fifty-five thousand, one hundred fifty-five".