75985181821 has 2 divisors, whose sum is σ = 75985181822. Its totient is φ = 75985181820.

The previous prime is 75985181791. The next prime is 75985181827. The reversal of 75985181821 is 12818158957.

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., 39576725721 + 36408456100 = 198939^2 + 190810^2 .

It is a cyclic number.

It is not a de Polignac number, because 75985181821 - 2³³ = 67395247229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75985181827) 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, 37992590910 + 37992590911.

It is an arithmetic number, because the mean of its divisors is an integer number (37992590911).

Almost surely, 2^75985181821 is an apocalyptic number.

It is an amenable number.

75985181821 is a deficient number, since it is larger than the sum of its proper divisors (1).

75985181821 is an equidigital number, since it uses as much as digits as its factorization.

75985181821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1612800, while the sum is 55.

The spelling of 75985181821 in words is "seventy-five billion, nine hundred eighty-five million, one hundred eighty-one thousand, eight hundred twenty-one".