169157991 has 8 divisors (see below), whose sum is σ = 225633664. Its totient is φ = 112727160.

The previous prime is 169157987. The next prime is 169158037. The reversal of 169157991 is 199751961.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 169157991 - 2² = 169157987 is a prime.

It is a super-2 number, since 2×169157991² = 57228851838312162, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 169157991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (169157951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1105 + ... + 18426.

It is an arithmetic number, because the mean of its divisors is an integer number (28204208).

Almost surely, 2^169157991 is an apocalyptic number.

169157991 is a deficient number, since it is larger than the sum of its proper divisors (56475673).

169157991 is a wasteful number, since it uses less digits than its factorization.

169157991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22421.

The product of its digits is 153090, while the sum is 48.

The square root of 169157991 is about 13006.0751574024. The cubic root of 169157991 is about 553.0497150177.

The spelling of 169157991 in words is "one hundred sixty-nine million, one hundred fifty-seven thousand, nine hundred ninety-one".