163345661 has 4 divisors (see below), whose sum is σ = 168978300. Its totient is φ = 157713024.

The previous prime is 163345657. The next prime is 163345667. The reversal of 163345661 is 166543361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166543361 = 281 ⋅592681.

It can be written as a sum of positive squares in 2 ways, for example, as 69139225 + 94206436 = 8315^2 + 9706^2 .

It is a cyclic number.

It is not a de Polignac number, because 163345661 - 2² = 163345657 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 (163345667) 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, 2816276 + ... + 2816333.

It is an arithmetic number, because the mean of its divisors is an integer number (42244575).

Almost surely, 2^163345661 is an apocalyptic number.

It is an amenable number.

163345661 is a deficient number, since it is larger than the sum of its proper divisors (5632639).

163345661 is an equidigital number, since it uses as much as digits as its factorization.

163345661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5632638.

The product of its digits is 38880, while the sum is 35.

The square root of 163345661 is about 12780.6752951477. The cubic root of 163345661 is about 546.6414179214.

The spelling of 163345661 in words is "one hundred sixty-three million, three hundred forty-five thousand, six hundred sixty-one".