78781289929 has 2 divisors, whose sum is σ = 78781289930. Its totient is φ = 78781289928.

The previous prime is 78781289893. The next prime is 78781289987. The reversal of 78781289929 is 92998218787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76492624329 + 2288665600 = 276573^2 + 47840^2 .

It is an emirp because it is prime and its reverse (92998218787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78781289929 - 2⁹ = 78781289417 is a prime.

It is not a weakly prime, because it can be changed into another prime (78781287929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39390644964 + 39390644965.

It is an arithmetic number, because the mean of its divisors is an integer number (39390644965).

Almost surely, 2^78781289929 is an apocalyptic number.

It is an amenable number.

78781289929 is a deficient number, since it is larger than the sum of its proper divisors (1).

78781289929 is an equidigital number, since it uses as much as digits as its factorization.

78781289929 is an evil number, because the sum of its binary digits is even.

The product of its digits is 73156608, while the sum is 70.

The spelling of 78781289929 in words is "seventy-eight billion, seven hundred eighty-one million, two hundred eighty-nine thousand, nine hundred twenty-nine".