78129727 has 4 divisors (see below), whose sum is σ = 84139720. Its totient is φ = 72119736.

The previous prime is 78129721. The next prime is 78129761. The reversal of 78129727 is 72792187.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 78129727 - 2³ = 78129719 is a prime.

It is a super-2 number, since 2×78129727² = 12208508482189058, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78129721) 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 in 3 ways as a sum of consecutive naturals, for example, 3004977 + ... + 3005002.

It is an arithmetic number, because the mean of its divisors is an integer number (21034930).

Almost surely, 2^78129727 is an apocalyptic number.

78129727 is a deficient number, since it is larger than the sum of its proper divisors (6009993).

78129727 is a wasteful number, since it uses less digits than its factorization.

78129727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6009992.

The product of its digits is 98784, while the sum is 43.

The square root of 78129727 is about 8839.1021602875. The cubic root of 78129727 is about 427.5026084220.

The spelling of 78129727 in words is "seventy-eight million, one hundred twenty-nine thousand, seven hundred twenty-seven".