163655421 has 4 divisors (see below), whose sum is σ = 218207232. Its totient is φ = 109103612.

The previous prime is 163655399. The next prime is 163655431. The reversal of 163655421 is 124556361.

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: 124556361 = 3 ⋅41518787.

It is a cyclic number.

It is not a de Polignac number, because 163655421 - 2⁶ = 163655357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163655431) 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, 27275901 + ... + 27275906.

It is an arithmetic number, because the mean of its divisors is an integer number (54551808).

Almost surely, 2^163655421 is an apocalyptic number.

It is an amenable number.

163655421 is a deficient number, since it is larger than the sum of its proper divisors (54551811).

163655421 is an equidigital number, since it uses as much as digits as its factorization.

163655421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54551810.

The product of its digits is 21600, while the sum is 33.

The square root of 163655421 is about 12792.7878509729. The cubic root of 163655421 is about 546.9867402735.

The spelling of 163655421 in words is "one hundred sixty-three million, six hundred fifty-five thousand, four hundred twenty-one".