78399437923 has 2 divisors, whose sum is σ = 78399437924. Its totient is φ = 78399437922.

The previous prime is 78399437891. The next prime is 78399437953. The reversal of 78399437923 is 32973499387.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78399437923 - 2⁵ = 78399437891 is a prime.

It is a super-2 number, since 2×78399437923² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78399437953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39199718961 + 39199718962.

It is an arithmetic number, because the mean of its divisors is an integer number (39199718962).

Almost surely, 2^78399437923 is an apocalyptic number.

78399437923 is a deficient number, since it is larger than the sum of its proper divisors (1).

78399437923 is an equidigital number, since it uses as much as digits as its factorization.

78399437923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61725888, while the sum is 64.

The spelling of 78399437923 in words is "seventy-eight billion, three hundred ninety-nine million, four hundred thirty-seven thousand, nine hundred twenty-three".