20145155 has 4 divisors (see below), whose sum is σ = 24174192. Its totient is φ = 16116120.

The previous prime is 20145127. The next prime is 20145163. The reversal of 20145155 is 55154102.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-20145155 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 20145155.

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, 2014511 + ... + 2014520.

It is an arithmetic number, because the mean of its divisors is an integer number (6043548).

Almost surely, 2^20145155 is an apocalyptic number.

20145155 is a deficient number, since it is larger than the sum of its proper divisors (4029037).

20145155 is an equidigital number, since it uses as much as digits as its factorization.

20145155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4029036.

The product of its (nonzero) digits is 1000, while the sum is 23.

The square root of 20145155 is about 4488.3354375537. The cubic root of 20145155 is about 272.0968648299.

Adding to 20145155 its reverse (55154102), we get a palindrome (75299257).

The spelling of 20145155 in words is "twenty million, one hundred forty-five thousand, one hundred fifty-five".