161919827 has 4 divisors (see below), whose sum is σ = 163405440. Its totient is φ = 160434216.

The previous prime is 161919809. The next prime is 161919833. The reversal of 161919827 is 728919161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161919827 - 2⁶ = 161919763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161919887) 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, 742643 + ... + 742860.

It is an arithmetic number, because the mean of its divisors is an integer number (40851360).

Almost surely, 2^161919827 is an apocalyptic number.

161919827 is a deficient number, since it is larger than the sum of its proper divisors (1485613).

161919827 is a wasteful number, since it uses less digits than its factorization.

161919827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1485612.

The product of its digits is 54432, while the sum is 44.

The square root of 161919827 is about 12724.7721787072. The cubic root of 161919827 is about 545.0462346097.

The spelling of 161919827 in words is "one hundred sixty-one million, nine hundred nineteen thousand, eight hundred twenty-seven".