78743905 has 4 divisors (see below), whose sum is σ = 94492692. Its totient is φ = 62995120.

The previous prime is 78743893. The next prime is 78743909. The reversal of 78743905 is 50934787.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50934787 = 383 ⋅132989.

It can be written as a sum of positive squares in 2 ways, for example, as 60279696 + 18464209 = 7764^2 + 4297^2 .

It is not a de Polignac number, because 78743905 - 2⁹ = 78743393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78743909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7874386 + ... + 7874395.

It is an arithmetic number, because the mean of its divisors is an integer number (23623173).

Almost surely, 2^78743905 is an apocalyptic number.

It is an amenable number.

78743905 is a deficient number, since it is larger than the sum of its proper divisors (15748787).

78743905 is a wasteful number, since it uses less digits than its factorization.

78743905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15748786.

The product of its (nonzero) digits is 211680, while the sum is 43.

The square root of 78743905 is about 8873.7762536589. The cubic root of 78743905 is about 428.6198856056.

The spelling of 78743905 in words is "seventy-eight million, seven hundred forty-three thousand, nine hundred five".