1971018351761 has 2 divisors, whose sum is σ = 1971018351762. Its totient is φ = 1971018351760.

The previous prime is 1971018351751. The next prime is 1971018351763. The reversal of 1971018351761 is 1671538101791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1075120134400 + 895898217361 = 1036880^2 + 946519^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971018351761 - 2⁶ = 1971018351697 is a prime.

It is a super-2 number, since 2×1971018351761² (a number of 25 digits) contains 22 as substring.

Together with 1971018351763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1971018351763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 985509175880 + 985509175881.

It is an arithmetic number, because the mean of its divisors is an integer number (985509175881).

Almost surely, 2^{1971018351761} is an apocalyptic number.

It is an amenable number.

1971018351761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1971018351761 is an equidigital number, since it uses as much as digits as its factorization.

1971018351761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 317520, while the sum is 50.

The spelling of 1971018351761 in words is "one trillion, nine hundred seventy-one billion, eighteen million, three hundred fifty-one thousand, seven hundred sixty-one".