75494994781 has 2 divisors, whose sum is σ = 75494994782. Its totient is φ = 75494994780.

The previous prime is 75494994761. The next prime is 75494994821. The reversal of 75494994781 is 18749949457.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38874431556 + 36620563225 = 197166^2 + 191365^2 .

It is an emirp because it is prime and its reverse (18749949457) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 75494994781 - 2²¹ = 75492897629 is a prime.

It is a super-2 number, since 2×75494994781² (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 (75494994761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37747497390 + 37747497391.

It is an arithmetic number, because the mean of its divisors is an integer number (37747497391).

Almost surely, 2^75494994781 is an apocalyptic number.

It is an amenable number.

75494994781 is a deficient number, since it is larger than the sum of its proper divisors (1).

75494994781 is an equidigital number, since it uses as much as digits as its factorization.

75494994781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91445760, while the sum is 67.

The spelling of 75494994781 in words is "seventy-five billion, four hundred ninety-four million, nine hundred ninety-four thousand, seven hundred eighty-one".