163913021 has 4 divisors (see below), whose sum is σ = 166359552. Its totient is φ = 161466492.

The previous prime is 163912993. The next prime is 163913023. The reversal of 163913021 is 120319361.

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.

It is a cyclic number.

It is not a de Polignac number, because 163913021 - 2¹⁴ = 163896637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163913023) 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, 1223165 + ... + 1223298.

It is an arithmetic number, because the mean of its divisors is an integer number (41589888).

Almost surely, 2^163913021 is an apocalyptic number.

It is an amenable number.

163913021 is a deficient number, since it is larger than the sum of its proper divisors (2446531).

163913021 is an equidigital number, since it uses as much as digits as its factorization.

163913021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2446530.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 163913021 is about 12802.8520650674. The cubic root of 163913021 is about 547.2735826294.

The spelling of 163913021 in words is "one hundred sixty-three million, nine hundred thirteen thousand, twenty-one".