155811807775 has 24 divisors (see below), whose sum is σ = 217115166240. Its totient is φ = 110058368640.

The previous prime is 155811807773. The next prime is 155811807787. The reversal of 155811807775 is 577708118551.

It is not a de Polignac number, because 155811807775 - 2¹ = 155811807773 is a prime.

It is a super-2 number, since 2×155811807775² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155811807773) 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 23 ways as a sum of consecutive naturals, for example, 10414720 + ... + 10429669.

It is an arithmetic number, because the mean of its divisors is an integer number (9046465260).

Almost surely, 2^155811807775 is an apocalyptic number.

155811807775 is a deficient number, since it is larger than the sum of its proper divisors (61303358465).

155811807775 is a wasteful number, since it uses less digits than its factorization.

155811807775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20844435 (or 20844430 counting only the distinct ones).

The product of its (nonzero) digits is 2744000, while the sum is 55.

The spelling of 155811807775 in words is "one hundred fifty-five billion, eight hundred eleven million, eight hundred seven thousand, seven hundred seventy-five".