161665363 has 4 divisors (see below), whose sum is σ = 163711840. Its totient is φ = 159618888.

The previous prime is 161665333. The next prime is 161665373. The reversal of 161665363 is 363566161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161665363 is a prime.

It is a super-2 number, since 2×161665363² = 52271379187843538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161665333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1023120 + ... + 1023277.

It is an arithmetic number, because the mean of its divisors is an integer number (40927960).

Almost surely, 2^161665363 is an apocalyptic number.

161665363 is a deficient number, since it is larger than the sum of its proper divisors (2046477).

161665363 is an equidigital number, since it uses as much as digits as its factorization.

161665363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2046476.

The product of its digits is 58320, while the sum is 37.

The square root of 161665363 is about 12714.7694827708. The cubic root of 161665363 is about 544.7605636782.

The spelling of 161665363 in words is "one hundred sixty-one million, six hundred sixty-five thousand, three hundred sixty-three".