78431629 has 2 divisors, whose sum is σ = 78431630. Its totient is φ = 78431628.

The previous prime is 78431623. The next prime is 78431653. The reversal of 78431629 is 92613487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76090729 + 2340900 = 8723^2 + 1530^2 .

It is a cyclic number.

It is not a de Polignac number, because 78431629 - 2³ = 78431621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78431591 and 78431600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78431621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39215814 + 39215815.

It is an arithmetic number, because the mean of its divisors is an integer number (39215815).

Almost surely, 2^78431629 is an apocalyptic number.

It is an amenable number.

78431629 is a deficient number, since it is larger than the sum of its proper divisors (1).

78431629 is an equidigital number, since it uses as much as digits as its factorization.

78431629 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 78431629 is about 8856.1633340855. The cubic root of 78431629 is about 428.0525399879.

The spelling of 78431629 in words is "seventy-eight million, four hundred thirty-one thousand, six hundred twenty-nine".