201000209981 has 2 divisors, whose sum is σ = 201000209982. Its totient is φ = 201000209980.

The previous prime is 201000209957. The next prime is 201000210007. The reversal of 201000209981 is 189902000102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169851136900 + 31149073081 = 412130^2 + 176491^2 .

It is a cyclic number.

It is not a de Polignac number, because 201000209981 - 2¹⁰ = 201000208957 is a prime.

It is a super-2 number, since 2×201000209981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201900209981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100500104990 + 100500104991.

It is an arithmetic number, because the mean of its divisors is an integer number (100500104991).

Almost surely, 2^201000209981 is an apocalyptic number.

It is an amenable number.

201000209981 is a deficient number, since it is larger than the sum of its proper divisors (1).

201000209981 is an equidigital number, since it uses as much as digits as its factorization.

201000209981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 32.

The spelling of 201000209981 in words is "two hundred one billion, two hundred nine thousand, nine hundred eighty-one".