1973542707781 has 2 divisors, whose sum is σ = 1973542707782.
Its totient is φ = 1973542707780.
The previous prime is 1973542707769. The next prime is 1973542707791. The reversal of 1973542707781 is 1877072453791.
It is a happy number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 1148005102500 + 825537605281 = 1071450^2 + 908591^2
It is a cyclic number.
It is not a de Polignac number, because 1973542707781 - 213 = 1973542699589 is a prime.
It is a super-2 number, since 2×19735427077812 (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 (1973542707791) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (19) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986771353890 + 986771353891.
It is an arithmetic number, because the mean of its divisors is an integer number (986771353891).
Almost surely, 21973542707781 is an apocalyptic number.
It is an amenable number.
1973542707781 is a deficient number, since it is larger than the sum of its proper divisors (1).
1973542707781 is an equidigital number, since it uses as much as digits as its factorization.
1973542707781 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 20744640, while the sum is 61.
The spelling of 1973542707781 in words is "one trillion, nine hundred seventy-three billion, five hundred forty-two million, seven hundred seven thousand, seven hundred eighty-one".