201891281 has 2 divisors, whose sum is σ = 201891282. Its totient is φ = 201891280.

The previous prime is 201891259. The next prime is 201891293. The reversal of 201891281 is 182198102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179801281 + 22090000 = 13409^2 + 4700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201891281 is a prime.

It is a super-2 number, since 2×201891281² = 81520178687641922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (201891211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100945640 + 100945641.

It is an arithmetic number, because the mean of its divisors is an integer number (100945641).

Almost surely, 2^201891281 is an apocalyptic number.

It is an amenable number.

201891281 is a deficient number, since it is larger than the sum of its proper divisors (1).

201891281 is an equidigital number, since it uses as much as digits as its factorization.

201891281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 32.

The square root of 201891281 is about 14208.8451677116. The cubic root of 201891281 is about 586.6411471266.

The spelling of 201891281 in words is "two hundred one million, eight hundred ninety-one thousand, two hundred eighty-one".