78172817287 has 2 divisors, whose sum is σ = 78172817288. Its totient is φ = 78172817286.

The previous prime is 78172817279. The next prime is 78172817293. The reversal of 78172817287 is 78271827187.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78172817287 - 2³ = 78172817279 is a prime.

It is a super-2 number, since 2×78172817287² (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 (78172817227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39086408643 + 39086408644.

It is an arithmetic number, because the mean of its divisors is an integer number (39086408644).

Almost surely, 2^78172817287 is an apocalyptic number.

78172817287 is a deficient number, since it is larger than the sum of its proper divisors (1).

78172817287 is an equidigital number, since it uses as much as digits as its factorization.

78172817287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4917248, while the sum is 58.

The spelling of 78172817287 in words is "seventy-eight billion, one hundred seventy-two million, eight hundred seventeen thousand, two hundred eighty-seven".