1997909934281 has 2 divisors, whose sum is σ = 1997909934282. Its totient is φ = 1997909934280.

The previous prime is 1997909934247. The next prime is 1997909934287. The reversal of 1997909934281 is 1824399097991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1950097738681 + 47812195600 = 1396459^2 + 218660^2 .

It is a cyclic number.

It is not a de Polignac number, because 1997909934281 - 2⁶ = 1997909934217 is a prime.

It is a super-2 number, since 2×1997909934281² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1997909934287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998954967140 + 998954967141.

It is an arithmetic number, because the mean of its divisors is an integer number (998954967141).

Almost surely, 2^{1997909934281} is an apocalyptic number.

It is an amenable number.

1997909934281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997909934281 is an equidigital number, since it uses as much as digits as its factorization.

1997909934281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 79361856, while the sum is 71.

The spelling of 1997909934281 in words is "one trillion, nine hundred ninety-seven billion, nine hundred nine million, nine hundred thirty-four thousand, two hundred eighty-one".