163889261 has 2 divisors, whose sum is σ = 163889262. Its totient is φ = 163889260.

The previous prime is 163889251. The next prime is 163889263. The reversal of 163889261 is 162988361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147161161 + 16728100 = 12131^2 + 4090^2 .

It is a cyclic number.

It is not a de Polignac number, because 163889261 - 2¹⁰ = 163888237 is a prime.

It is a super-2 number, since 2×163889261² = 53719379742252242, which contains 22 as substring.

Together with 163889263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163889263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81944630 + 81944631.

It is an arithmetic number, because the mean of its divisors is an integer number (81944631).

Almost surely, 2^163889261 is an apocalyptic number.

It is an amenable number.

163889261 is a deficient number, since it is larger than the sum of its proper divisors (1).

163889261 is an equidigital number, since it uses as much as digits as its factorization.

163889261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 44.

The square root of 163889261 is about 12801.9241131949. The cubic root of 163889261 is about 547.2471380175.

The spelling of 163889261 in words is "one hundred sixty-three million, eight hundred eighty-nine thousand, two hundred sixty-one".