78206881693 has 2 divisors, whose sum is σ = 78206881694. Its totient is φ = 78206881692.

The previous prime is 78206881619. The next prime is 78206881733. The reversal of 78206881693 is 39618860287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77625203769 + 581677924 = 278613^2 + 24118^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78206881693 is a prime.

It is a super-2 number, since 2×78206881693² (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 (78206881603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39103440846 + 39103440847.

It is an arithmetic number, because the mean of its divisors is an integer number (39103440847).

Almost surely, 2^78206881693 is an apocalyptic number.

It is an amenable number.

78206881693 is a deficient number, since it is larger than the sum of its proper divisors (1).

78206881693 is an equidigital number, since it uses as much as digits as its factorization.

78206881693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6967296, while the sum is 58.

The spelling of 78206881693 in words is "seventy-eight billion, two hundred six million, eight hundred eighty-one thousand, six hundred ninety-three".