155212105 has 4 divisors (see below), whose sum is σ = 186254532. Its totient is φ = 124169680.

The previous prime is 155212103. The next prime is 155212117. The reversal of 155212105 is 501212551.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 47114496 + 108097609 = 6864^2 + 10397^2 .

It is not a de Polignac number, because 155212105 - 2¹ = 155212103 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155212103) 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, 15521206 + ... + 15521215.

It is an arithmetic number, because the mean of its divisors is an integer number (46563633).

Almost surely, 2^155212105 is an apocalyptic number.

It is an amenable number.

155212105 is a deficient number, since it is larger than the sum of its proper divisors (31042427).

155212105 is an equidigital number, since it uses as much as digits as its factorization.

155212105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31042426.

The product of its (nonzero) digits is 500, while the sum is 22.

The square root of 155212105 is about 12458.4150276028. The cubic root of 155212105 is about 537.4134477545.

Adding to 155212105 its reverse (501212551), we get a palindrome (656424656).

The spelling of 155212105 in words is "one hundred fifty-five million, two hundred twelve thousand, one hundred five".