78384046781 has 2 divisors, whose sum is σ = 78384046782. Its totient is φ = 78384046780.

The previous prime is 78384046751. The next prime is 78384046877. The reversal of 78384046781 is 18764048387.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68437176025 + 9946870756 = 261605^2 + 99734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78384046781 is a prime.

It is a super-2 number, since 2×78384046781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78384046721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39192023390 + 39192023391.

It is an arithmetic number, because the mean of its divisors is an integer number (39192023391).

Almost surely, 2^78384046781 is an apocalyptic number.

It is an amenable number.

78384046781 is a deficient number, since it is larger than the sum of its proper divisors (1).

78384046781 is an equidigital number, since it uses as much as digits as its factorization.

78384046781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7225344, while the sum is 56.

The spelling of 78384046781 in words is "seventy-eight billion, three hundred eighty-four million, forty-six thousand, seven hundred eighty-one".