158696991 has 6 divisors (see below), whose sum is σ = 229229000. Its totient is φ = 105797988.

The previous prime is 158696977. The next prime is 158697001. The reversal of 158696991 is 199696851.

It is not a de Polignac number, because 158696991 - 2¹⁴ = 158680607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (158696191) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8816491 + ... + 8816508.

Almost surely, 2^158696991 is an apocalyptic number.

158696991 is a deficient number, since it is larger than the sum of its proper divisors (70532009).

158696991 is a wasteful number, since it uses less digits than its factorization.

158696991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17633005 (or 17633002 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The square root of 158696991 is about 12597.4993947212. The cubic root of 158696991 is about 541.4057918332.

The spelling of 158696991 in words is "one hundred fifty-eight million, six hundred ninety-six thousand, nine hundred ninety-one".