155612993 has 2 divisors, whose sum is σ = 155612994. Its totient is φ = 155612992.

The previous prime is 155612969. The next prime is 155613037. The reversal of 155612993 is 399216551.

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., 98565184 + 57047809 = 9928^2 + 7553^2 .

It is an emirp because it is prime and its reverse (399216551) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155612993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155612993.

It is not a weakly prime, because it can be changed into another prime (155612903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77806496 + 77806497.

It is an arithmetic number, because the mean of its divisors is an integer number (77806497).

Almost surely, 2^155612993 is an apocalyptic number.

It is an amenable number.

155612993 is a deficient number, since it is larger than the sum of its proper divisors (1).

155612993 is an equidigital number, since it uses as much as digits as its factorization.

155612993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72900, while the sum is 41.

The square root of 155612993 is about 12474.4936971406. The cubic root of 155612993 is about 537.8757342567.

The spelling of 155612993 in words is "one hundred fifty-five million, six hundred twelve thousand, nine hundred ninety-three".