163128661 has 4 divisors (see below), whose sum is σ = 171714400. Its totient is φ = 154542924.

The previous prime is 163128631. The next prime is 163128689. The reversal of 163128661 is 166821361.

It is a happy number.

163128661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166821361 = 7 ⋅23831623.

It is a cyclic number.

It is not a de Polignac number, because 163128661 - 2⁹ = 163128149 is a prime.

It is a super-2 number, since 2×163128661² = 53221920079305842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163128611) 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, 4292841 + ... + 4292878.

It is an arithmetic number, because the mean of its divisors is an integer number (42928600).

Almost surely, 2^163128661 is an apocalyptic number.

It is an amenable number.

163128661 is a deficient number, since it is larger than the sum of its proper divisors (8585739).

163128661 is an equidigital number, since it uses as much as digits as its factorization.

163128661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8585738.

The product of its digits is 10368, while the sum is 34.

The square root of 163128661 is about 12772.1830945223. The cubic root of 163128661 is about 546.3992448633.

The spelling of 163128661 in words is "one hundred sixty-three million, one hundred twenty-eight thousand, six hundred sixty-one".