161827391 has 8 divisors (see below), whose sum is σ = 179870544. Its totient is φ = 144339520.

The previous prime is 161827387. The next prime is 161827417. The reversal of 161827391 is 193728161.

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

It is a cyclic number.

It is not a de Polignac number, because 161827391 - 2² = 161827387 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 (161827321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138206 + ... + 139371.

It is an arithmetic number, because the mean of its divisors is an integer number (22483818).

Almost surely, 2^161827391 is an apocalyptic number.

161827391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161827391 is a deficient number, since it is larger than the sum of its proper divisors (18043153).

161827391 is a wasteful number, since it uses less digits than its factorization.

161827391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277641.

The product of its digits is 18144, while the sum is 38.

The square root of 161827391 is about 12721.1395322903. The cubic root of 161827391 is about 544.9424970894.

The spelling of 161827391 in words is "one hundred sixty-one million, eight hundred twenty-seven thousand, three hundred ninety-one".