167991389 has 4 divisors (see below), whose sum is σ = 168099360. Its totient is φ = 167883420.

The previous prime is 167991361. The next prime is 167991401. The reversal of 167991389 is 983199761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 983199761 = 571 ⋅1721891.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-167991389 is a prime.

It is a super-2 number, since 2×167991389² = 56442213556298642, 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 167991389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (167991319) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51617 + ... + 54774.

It is an arithmetic number, because the mean of its divisors is an integer number (42024840).

Almost surely, 2^167991389 is an apocalyptic number.

It is an amenable number.

167991389 is a deficient number, since it is larger than the sum of its proper divisors (107971).

167991389 is a wasteful number, since it uses less digits than its factorization.

167991389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107970.

The product of its digits is 734832, while the sum is 53.

The square root of 167991389 is about 12961.1492160225. The cubic root of 167991389 is about 551.7754076961.

The spelling of 167991389 in words is "one hundred sixty-seven million, nine hundred ninety-one thousand, three hundred eighty-nine".