155131213 has 2 divisors, whose sum is σ = 155131214. Its totient is φ = 155131212.

The previous prime is 155131199. The next prime is 155131231. The reversal of 155131213 is 312131551.

Together with next prime (155131231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129345129 + 25786084 = 11373^2 + 5078^2 .

It is a cyclic number.

It is not a de Polignac number, because 155131213 - 2¹³ = 155123021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155131243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77565606 + 77565607.

It is an arithmetic number, because the mean of its divisors is an integer number (77565607).

Almost surely, 2^155131213 is an apocalyptic number.

It is an amenable number.

155131213 is a deficient number, since it is larger than the sum of its proper divisors (1).

155131213 is an equidigital number, since it uses as much as digits as its factorization.

155131213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 450, while the sum is 22.

The square root of 155131213 is about 12455.1681241162. The cubic root of 155131213 is about 537.3200701514.

Adding to 155131213 its reverse (312131551), we get a palindrome (467262764).

The spelling of 155131213 in words is "one hundred fifty-five million, one hundred thirty-one thousand, two hundred thirteen".