163556347021 has 4 divisors (see below), whose sum is σ = 163956240700. Its totient is φ = 163156453344.

The previous prime is 163556346971. The next prime is 163556347027. The reversal of 163556347021 is 120743655361.

163556347021 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.

It can be written as a sum of positive squares in 2 ways, for example, as 127530408996 + 36025938025 = 357114^2 + 189805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-163556347021 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 (163556347027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199946226 + ... + 199947043.

It is an arithmetic number, because the mean of its divisors is an integer number (40989060175).

Almost surely, 2^163556347021 is an apocalyptic number.

It is an amenable number.

163556347021 is a deficient number, since it is larger than the sum of its proper divisors (399893679).

163556347021 is an equidigital number, since it uses as much as digits as its factorization.

163556347021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399893678.

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 163556347021 in words is "one hundred sixty-three billion, five hundred fifty-six million, three hundred forty-seven thousand, twenty-one".