155979744989 has 18 divisors (see below), whose sum is σ = 173212258170. Its totient is φ = 140421525376.

The previous prime is 155979744961. The next prime is 155979745027. The reversal of 155979744989 is 989447979551.

It can be written as a sum of positive squares in 3 ways, for example, as 119756139364 + 36223605625 = 346058^2 + 190325^2 .

It is not a de Polignac number, because 155979744989 - 2³² = 151684777693 is a prime.

It is a super-2 number, since 2×155979744989² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155979744589) 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 in 17 ways as a sum of consecutive naturals, for example, 357254 + ... + 663015.

Almost surely, 2^155979744989 is an apocalyptic number.

It is an amenable number.

155979744989 is a deficient number, since it is larger than the sum of its proper divisors (17232513181).

155979744989 is a wasteful number, since it uses less digits than its factorization.

155979744989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020349 (or 1020309 counting only the distinct ones).

The product of its digits is 1028764800, while the sum is 77.

The spelling of 155979744989 in words is "one hundred fifty-five billion, nine hundred seventy-nine million, seven hundred forty-four thousand, nine hundred eighty-nine".