155121133 has 2 divisors, whose sum is σ = 155121134. Its totient is φ = 155121132.

The previous prime is 155121121. The next prime is 155121143. The reversal of 155121133 is 331121551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87272964 + 67848169 = 9342^2 + 8237^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155121133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155121143) 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, 77560566 + 77560567.

It is an arithmetic number, because the mean of its divisors is an integer number (77560567).

Almost surely, 2^155121133 is an apocalyptic number.

It is an amenable number.

155121133 is a deficient number, since it is larger than the sum of its proper divisors (1).

155121133 is an equidigital number, since it uses as much as digits as its factorization.

155121133 is an odious number, because the sum of its binary digits is odd.

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

The square root of 155121133 is about 12454.7634662405. The cubic root of 155121133 is about 537.3084320387.

Adding to 155121133 its reverse (331121551), we get a palindrome (486242684).

The spelling of 155121133 in words is "one hundred fifty-five million, one hundred twenty-one thousand, one hundred thirty-three".