78537474738881 has 2 divisors, whose sum is σ = 78537474738882. Its totient is φ = 78537474738880.

The previous prime is 78537474738823. The next prime is 78537474738907. The reversal of 78537474738881 is 18883747473587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41323619439025 + 37213855299856 = 6428345^2 + 6100316^2 .

It is a cyclic number.

It is not a de Polignac number, because 78537474738881 - 2¹⁸ = 78537474476737 is a prime.

It is a super-2 number, since 2×78537474738881² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 78537474738796 and 78537474738805.

It is not a weakly prime, because it can be changed into another prime (78537474732881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39268737369440 + 39268737369441.

It is an arithmetic number, because the mean of its divisors is an integer number (39268737369441).

Almost surely, 2^{78537474738881} is an apocalyptic number.

It is an amenable number.

78537474738881 is a deficient number, since it is larger than the sum of its proper divisors (1).

78537474738881 is an equidigital number, since it uses as much as digits as its factorization.

78537474738881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7080837120, while the sum is 80.

The spelling of 78537474738881 in words is "seventy-eight trillion, five hundred thirty-seven billion, four hundred seventy-four million, seven hundred thirty-eight thousand, eight hundred eighty-one".