168164991 has 54 divisors (see below), whose sum is σ = 269958312. Its totient is φ = 104713560.

The previous prime is 168164977. The next prime is 168164999. The reversal of 168164991 is 199461861.

It is a de Polignac number, because none of the positive numbers 2^k-168164991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168164999) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2368486 + ... + 2368556.

It is an arithmetic number, because the mean of its divisors is an integer number (4999228).

Almost surely, 2^168164991 is an apocalyptic number.

168164991 is a deficient number, since it is larger than the sum of its proper divisors (101793321).

168164991 is an frugal number, since it uses more digits than its factorization.

168164991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133 (or 93 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 168164991 is about 12967.8445009184. The cubic root of 168164991 is about 551.9654101671.

The spelling of 168164991 in words is "one hundred sixty-eight million, one hundred sixty-four thousand, nine hundred ninety-one".