155109945581 has 2 divisors, whose sum is σ = 155109945582. Its totient is φ = 155109945580.

The previous prime is 155109945559. The next prime is 155109945629. The reversal of 155109945581 is 185549901551.

155109945581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147583515556 + 7526430025 = 384166^2 + 86755^2 .

It is a cyclic number.

It is not a de Polignac number, because 155109945581 - 2¹⁴ = 155109929197 is a prime.

It is a super-2 number, since 2×155109945581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155109945511) 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, 77554972790 + 77554972791.

It is an arithmetic number, because the mean of its divisors is an integer number (77554972791).

Almost surely, 2^155109945581 is an apocalyptic number.

It is an amenable number.

155109945581 is a deficient number, since it is larger than the sum of its proper divisors (1).

155109945581 is an equidigital number, since it uses as much as digits as its factorization.

155109945581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620000, while the sum is 53.

The spelling of 155109945581 in words is "one hundred fifty-five billion, one hundred nine million, nine hundred forty-five thousand, five hundred eighty-one".