78447174881 has 2 divisors, whose sum is σ = 78447174882. Its totient is φ = 78447174880.

The previous prime is 78447174763. The next prime is 78447174893. The reversal of 78447174881 is 18847174487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48305006656 + 30142168225 = 219784^2 + 173615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78447174881 is a prime.

It is a super-2 number, since 2×78447174881² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78447174881.

It is not a weakly prime, because it can be changed into another prime (78447173881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39223587440 + 39223587441.

It is an arithmetic number, because the mean of its divisors is an integer number (39223587441).

Almost surely, 2^78447174881 is an apocalyptic number.

It is an amenable number.

78447174881 is a deficient number, since it is larger than the sum of its proper divisors (1).

78447174881 is an equidigital number, since it uses as much as digits as its factorization.

78447174881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11239424, while the sum is 59.

The spelling of 78447174881 in words is "seventy-eight billion, four hundred forty-seven million, one hundred seventy-four thousand, eight hundred eighty-one".