20208155 has 16 divisors (see below), whose sum is σ = 28011744. Its totient is φ = 13831680.

The previous prime is 20208109. The next prime is 20208163. The reversal of 20208155 is 55180202.

It is not a de Polignac number, because 20208155 - 2¹² = 20204059 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20208155.

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, 9872 + ... + 11741.

It is an arithmetic number, because the mean of its divisors is an integer number (1750734).

Almost surely, 2^20208155 is an apocalyptic number.

20208155 is a deficient number, since it is larger than the sum of its proper divisors (7803589).

20208155 is a wasteful number, since it uses less digits than its factorization.

20208155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21646.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 20208155 is about 4495.3481511447. The cubic root of 20208155 is about 272.3802127607.

Adding to 20208155 its reverse (55180202), we get a palindrome (75388357).

The spelling of 20208155 in words is "twenty million, two hundred eight thousand, one hundred fifty-five".