20102155 has 4 divisors (see below), whose sum is σ = 24122592. Its totient is φ = 16081720.

The previous prime is 20102153. The next prime is 20102213. The reversal of 20102155 is 55120102.

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

It is not a de Polignac number, because 20102155 - 2¹ = 20102153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20102153) 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, 2010211 + ... + 2010220.

It is an arithmetic number, because the mean of its divisors is an integer number (6030648).

Almost surely, 2^20102155 is an apocalyptic number.

20102155 is a deficient number, since it is larger than the sum of its proper divisors (4020437).

20102155 is an equidigital number, since it uses as much as digits as its factorization.

20102155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4020436.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 20102155 is about 4483.5426840836. The cubic root of 20102155 is about 271.9031292514.

Adding to 20102155 its reverse (55120102), we get a palindrome (75222257).

The spelling of 20102155 in words is "twenty million, one hundred two thousand, one hundred fifty-five".