155581235989 has 2 divisors, whose sum is σ = 155581235990. Its totient is φ = 155581235988.

The previous prime is 155581235939. The next prime is 155581236017. The reversal of 155581235989 is 989532185551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 146044736964 + 9536499025 = 382158^2 + 97655^2 .

It is a cyclic number.

It is not a de Polignac number, because 155581235989 - 2¹³ = 155581227797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155581235939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77790617994 + 77790617995.

It is an arithmetic number, because the mean of its divisors is an integer number (77790617995).

Almost surely, 2^155581235989 is an apocalyptic number.

It is an amenable number.

155581235989 is a deficient number, since it is larger than the sum of its proper divisors (1).

155581235989 is an equidigital number, since it uses as much as digits as its factorization.

155581235989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440000, while the sum is 61.

The spelling of 155581235989 in words is "one hundred fifty-five billion, five hundred eighty-one million, two hundred thirty-five thousand, nine hundred eighty-nine".