78374689691 has 2 divisors, whose sum is σ = 78374689692. Its totient is φ = 78374689690.

The previous prime is 78374689681. The next prime is 78374689781. The reversal of 78374689691 is 19698647387.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78374689691 - 2³⁴ = 61194820507 is a prime.

It is a super-2 number, since 2×78374689691² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78374689661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39187344845 + 39187344846.

It is an arithmetic number, because the mean of its divisors is an integer number (39187344846).

Almost surely, 2^78374689691 is an apocalyptic number.

78374689691 is a deficient number, since it is larger than the sum of its proper divisors (1).

78374689691 is an equidigital number, since it uses as much as digits as its factorization.

78374689691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 109734912, while the sum is 68.

The spelling of 78374689691 in words is "seventy-eight billion, three hundred seventy-four million, six hundred eighty-nine thousand, six hundred ninety-one".