78679109 has 2 divisors, whose sum is σ = 78679110. Its totient is φ = 78679108.

The previous prime is 78679099. The next prime is 78679151. The reversal of 78679109 is 90197687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78676900 + 2209 = 8870^2 + 47^2 .

It is a cyclic number.

It is not a de Polignac number, because 78679109 - 2¹⁶ = 78613573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78679169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39339554 + 39339555.

It is an arithmetic number, because the mean of its divisors is an integer number (39339555).

Almost surely, 2^78679109 is an apocalyptic number.

It is an amenable number.

78679109 is a deficient number, since it is larger than the sum of its proper divisors (1).

78679109 is an equidigital number, since it uses as much as digits as its factorization.

78679109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 78679109 is about 8870.1245199828. The cubic root of 78679109 is about 428.5022871899.

It can be divided in two parts, 78679 and 109, that multiplied together give a triangular number (8576011 = T₄₁₄₁).

The spelling of 78679109 in words is "seventy-eight million, six hundred seventy-nine thousand, one hundred nine".