78123275731 has 2 divisors, whose sum is σ = 78123275732. Its totient is φ = 78123275730.

The previous prime is 78123275729. The next prime is 78123275803. The reversal of 78123275731 is 13757232187.

It is a weak prime.

It is an emirp because it is prime and its reverse (13757232187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78123275731 - 2¹ = 78123275729 is a prime.

It is a super-2 number, since 2×78123275731² (a number of 23 digits) contains 22 as substring.

Together with 78123275729, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (78123255731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39061637865 + 39061637866.

It is an arithmetic number, because the mean of its divisors is an integer number (39061637866).

Almost surely, 2^78123275731 is an apocalyptic number.

78123275731 is a deficient number, since it is larger than the sum of its proper divisors (1).

78123275731 is an equidigital number, since it uses as much as digits as its factorization.

78123275731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 493920, while the sum is 46.

The spelling of 78123275731 in words is "seventy-eight billion, one hundred twenty-three million, two hundred seventy-five thousand, seven hundred thirty-one".