75408766781 has 2 divisors, whose sum is σ = 75408766782. Its totient is φ = 75408766780.

The previous prime is 75408766757. The next prime is 75408766837. The reversal of 75408766781 is 18766780457.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52307806681 + 23100960100 = 228709^2 + 151990^2 .

It is a cyclic number.

It is not a de Polignac number, because 75408766781 - 2⁶ = 75408766717 is a prime.

It is a super-2 number, since 2×75408766781² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 75408766781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75408766711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37704383390 + 37704383391.

It is an arithmetic number, because the mean of its divisors is an integer number (37704383391).

Almost surely, 2^75408766781 is an apocalyptic number.

It is an amenable number.

75408766781 is a deficient number, since it is larger than the sum of its proper divisors (1).

75408766781 is an equidigital number, since it uses as much as digits as its factorization.

75408766781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15805440, while the sum is 59.

The spelling of 75408766781 in words is "seventy-five billion, four hundred eight million, seven hundred sixty-six thousand, seven hundred eighty-one".