155561450017 has 2 divisors, whose sum is σ = 155561450018. Its totient is φ = 155561450016.

The previous prime is 155561449921. The next prime is 155561450071. The reversal of 155561450017 is 710054165551.

Together with next prime (155561450071) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95594745856 + 59966704161 = 309184^2 + 244881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155561450017 is a prime.

It is not a weakly prime, because it can be changed into another prime (155561450917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77780725008 + 77780725009.

It is an arithmetic number, because the mean of its divisors is an integer number (77780725009).

Almost surely, 2^155561450017 is an apocalyptic number.

It is an amenable number.

155561450017 is a deficient number, since it is larger than the sum of its proper divisors (1).

155561450017 is an equidigital number, since it uses as much as digits as its factorization.

155561450017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 105000, while the sum is 40.

The spelling of 155561450017 in words is "one hundred fifty-five billion, five hundred sixty-one million, four hundred fifty thousand, seventeen".