78247422023891 has 2 divisors, whose sum is σ = 78247422023892. Its totient is φ = 78247422023890.

The previous prime is 78247422023767. The next prime is 78247422023933. The reversal of 78247422023891 is 19832022474287.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78247422023891 is a prime.

It is a super-2 number, since 2×78247422023891² (a number of 29 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 78247422023891.

It is not a weakly prime, because it can be changed into another prime (78247422623891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39123711011945 + 39123711011946.

It is an arithmetic number, because the mean of its divisors is an integer number (39123711011946).

Almost surely, 2^{78247422023891} is an apocalyptic number.

78247422023891 is a deficient number, since it is larger than the sum of its proper divisors (1).

78247422023891 is an equidigital number, since it uses as much as digits as its factorization.

78247422023891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21676032, while the sum is 59.

The spelling of 78247422023891 in words is "seventy-eight trillion, two hundred forty-seven billion, four hundred twenty-two million, twenty-three thousand, eight hundred ninety-one".