78239913 has 8 divisors (see below), whose sum is σ = 106539648. Its totient is φ = 51050064.

The previous prime is 78239893. The next prime is 78239923. The reversal of 78239913 is 31993287.

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

It is not a de Polignac number, because 78239913 - 2⁹ = 78239401 is a prime.

It is a super-2 number, since 2×78239913² = 12242967972495138, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78239923) 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 7 ways as a sum of consecutive naturals, for example, 277306 + ... + 277587.

It is an arithmetic number, because the mean of its divisors is an integer number (13317456).

Almost surely, 2^78239913 is an apocalyptic number.

It is an amenable number.

78239913 is a deficient number, since it is larger than the sum of its proper divisors (28299735).

78239913 is a wasteful number, since it uses less digits than its factorization.

78239913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554943.

The product of its digits is 81648, while the sum is 42.

The square root of 78239913 is about 8845.3328371520. The cubic root of 78239913 is about 427.7034823516.

The spelling of 78239913 in words is "seventy-eight million, two hundred thirty-nine thousand, nine hundred thirteen".