78840015 has 8 divisors (see below), whose sum is σ = 126144048. Its totient is φ = 42048000.

The previous prime is 78839953. The next prime is 78840023. The reversal of 78840015 is 51004887.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78840015 - 2¹⁵ = 78807247 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2627986 + ... + 2628015.

It is an arithmetic number, because the mean of its divisors is an integer number (15768006).

Almost surely, 2^78840015 is an apocalyptic number.

78840015 is a deficient number, since it is larger than the sum of its proper divisors (47304033).

78840015 is a wasteful number, since it uses less digits than its factorization.

78840015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5256009.

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 78840015 is about 8879.1899968409. The cubic root of 78840015 is about 428.7941971228.

The spelling of 78840015 in words is "seventy-eight million, eight hundred forty thousand, fifteen".