78399429761 has 2 divisors, whose sum is σ = 78399429762. Its totient is φ = 78399429760.

The previous prime is 78399429709. The next prime is 78399429767. The reversal of 78399429761 is 16792499387.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52193971600 + 26205458161 = 228460^2 + 161881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78399429761 is a prime.

It is a super-2 number, since 2×78399429761² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78399429767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199714880 + 39199714881.

It is an arithmetic number, because the mean of its divisors is an integer number (39199714881).

Almost surely, 2^78399429761 is an apocalyptic number.

It is an amenable number.

78399429761 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399429761 is an equidigital number, since it uses as much as digits as its factorization.

78399429761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41150592, while the sum is 65.

The spelling of 78399429761 in words is "seventy-eight billion, three hundred ninety-nine million, four hundred twenty-nine thousand, seven hundred sixty-one".