155999659491 has 24 divisors (see below), whose sum is σ = 242752189680. Its totient is φ = 95965747776.

The previous prime is 155999659457. The next prime is 155999659499. The reversal of 155999659491 is 194956999551.

155999659491 is a `hidden beast` number, since 1 + 559 + 9 + 9 + 65 + 9 + 4 + 9 + 1 = 666.

155999659491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 155999659491 - 2¹⁸ = 155999397347 is a prime.

It is a super-2 number, since 2×155999659491² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155999659499) 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 in 23 ways as a sum of consecutive naturals, for example, 96940 + ... + 566918.

It is an arithmetic number, because the mean of its divisors is an integer number (10114674570).

Almost surely, 2^155999659491 is an apocalyptic number.

155999659491 is a deficient number, since it is larger than the sum of its proper divisors (86752530189).

155999659491 is a wasteful number, since it uses less digits than its factorization.

155999659491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472835 (or 472832 counting only the distinct ones).

The product of its digits is 177147000, while the sum is 72.

The spelling of 155999659491 in words is "one hundred fifty-five billion, nine hundred ninety-nine million, six hundred fifty-nine thousand, four hundred ninety-one".