201017989 has 2 divisors, whose sum is σ = 201017990. Its totient is φ = 201017988.

The previous prime is 201017987. The next prime is 201018007. The reversal of 201017989 is 989710102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 123876900 + 77141089 = 11130^2 + 8783^2 .

It is a cyclic number.

It is not a de Polignac number, because 201017989 - 2¹ = 201017987 is a prime.

Together with 201017987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201017987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100508994 + 100508995.

It is an arithmetic number, because the mean of its divisors is an integer number (100508995).

Almost surely, 2^201017989 is an apocalyptic number.

It is an amenable number.

201017989 is a deficient number, since it is larger than the sum of its proper divisors (1).

201017989 is an equidigital number, since it uses as much as digits as its factorization.

201017989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 201017989 is about 14178.0812876778. The cubic root of 201017989 is about 585.7940749266.

The spelling of 201017989 in words is "two hundred one million, seventeen thousand, nine hundred eighty-nine".