161666263 has 8 divisors (see below), whose sum is σ = 176487696. Its totient is φ = 146865600.

The previous prime is 161666261. The next prime is 161666291. The reversal of 161666263 is 362666161.

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 161666263 - 2¹ = 161666261 is a prime.

It is a super-2 number, since 2×161666263² = 52271961184770338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161666261) 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, 14283 + ... + 22963.

It is an arithmetic number, because the mean of its divisors is an integer number (22060962).

Almost surely, 2^161666263 is an apocalyptic number.

161666263 is a deficient number, since it is larger than the sum of its proper divisors (14821433).

161666263 is a wasteful number, since it uses less digits than its factorization.

161666263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10385.

The product of its digits is 46656, while the sum is 37.

The square root of 161666263 is about 12714.8048746334. The cubic root of 161666263 is about 544.7615745804.

The spelling of 161666263 in words is "one hundred sixty-one million, six hundred sixty-six thousand, two hundred sixty-three".