2009999870981 has 2 divisors, whose sum is σ = 2009999870982. Its totient is φ = 2009999870980.

The previous prime is 2009999870971. The next prime is 2009999870987. The reversal of 2009999870981 is 1890789999002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1499583930625 + 510415940356 = 1224575^2 + 714434^2 .

It is a cyclic number.

It is not a de Polignac number, because 2009999870981 - 2⁶ = 2009999870917 is a prime.

It is a super-2 number, since 2×2009999870981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2009999870987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1004999935490 + 1004999935491.

It is an arithmetic number, because the mean of its divisors is an integer number (1004999935491).

Almost surely, 2^{2009999870981} is an apocalyptic number.

It is an amenable number.

2009999870981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2009999870981 is an equidigital number, since it uses as much as digits as its factorization.

2009999870981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52907904, while the sum is 71.

The spelling of 2009999870981 in words is "two trillion, nine billion, nine hundred ninety-nine million, eight hundred seventy thousand, nine hundred eighty-one".