163660397 has 4 divisors (see below), whose sum is σ = 167652156. Its totient is φ = 159668640.

The previous prime is 163660391. The next prime is 163660403. The reversal of 163660397 is 793066361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793066361 = 19259 ⋅41179.

It is an interprime number because it is at equal distance from previous prime (163660391) and next prime (163660403).

It can be written as a sum of positive squares in 2 ways, for example, as 2725801 + 160934596 = 1651^2 + 12686^2 .

It is a cyclic number.

It is not a de Polignac number, because 163660397 - 2¹² = 163656301 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 3991717 = 163660397 / (1 + 6 + 3 + 6 + 6 + 0 + 3 + 9 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163660391) 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, 1995818 + ... + 1995899.

It is an arithmetic number, because the mean of its divisors is an integer number (41913039).

Almost surely, 2^163660397 is an apocalyptic number.

It is an amenable number.

163660397 is a deficient number, since it is larger than the sum of its proper divisors (3991759).

163660397 is an equidigital number, since it uses as much as digits as its factorization.

163660397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3991758.

The product of its (nonzero) digits is 122472, while the sum is 41.

The square root of 163660397 is about 12792.9823340768. The cubic root of 163660397 is about 546.9922839913.

The spelling of 163660397 in words is "one hundred sixty-three million, six hundred sixty thousand, three hundred ninety-seven".