155105213 has 2 divisors, whose sum is σ = 155105214. Its totient is φ = 155105212.

The previous prime is 155105191. The next prime is 155105239. The reversal of 155105213 is 312501551.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113592964 + 41512249 = 10658^2 + 6443^2 .

It is a cyclic number.

It is not a de Polignac number, because 155105213 - 2¹² = 155101117 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155105243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77552606 + 77552607.

It is an arithmetic number, because the mean of its divisors is an integer number (77552607).

Almost surely, 2^155105213 is an apocalyptic number.

It is an amenable number.

155105213 is a deficient number, since it is larger than the sum of its proper divisors (1).

155105213 is an equidigital number, since it uses as much as digits as its factorization.

155105213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 155105213 is about 12454.1243369416. The cubic root of 155105213 is about 537.2900501829.

Adding to 155105213 its reverse (312501551), we get a palindrome (467606764).

The spelling of 155105213 in words is "one hundred fifty-five million, one hundred five thousand, two hundred thirteen".