78447068261 has 2 divisors, whose sum is σ = 78447068262. Its totient is φ = 78447068260.

The previous prime is 78447068257. The next prime is 78447068263. The reversal of 78447068261 is 16286074487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74471135236 + 3975933025 = 272894^2 + 63055^2 .

It is a cyclic number.

It is not a de Polignac number, because 78447068261 - 2² = 78447068257 is a prime.

Together with 78447068263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78447068263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39223534130 + 39223534131.

It is an arithmetic number, because the mean of its divisors is an integer number (39223534131).

Almost surely, 2^78447068261 is an apocalyptic number.

It is an amenable number.

78447068261 is a deficient number, since it is larger than the sum of its proper divisors (1).

78447068261 is an equidigital number, since it uses as much as digits as its factorization.

78447068261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3612672, while the sum is 53.

The spelling of 78447068261 in words is "seventy-eight billion, four hundred forty-seven million, sixty-eight thousand, two hundred sixty-one".