78728705 has 16 divisors (see below), whose sum is σ = 104519808. Its totient is φ = 56448000.

The previous prime is 78728693. The next prime is 78728719. The reversal of 78728705 is 50782787.

It is not a de Polignac number, because 78728705 - 2⁶ = 78728641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6176 + ... + 13985.

It is an arithmetic number, because the mean of its divisors is an integer number (6532488).

Almost surely, 2^78728705 is an apocalyptic number.

It is an amenable number.

78728705 is a deficient number, since it is larger than the sum of its proper divisors (25791103).

78728705 is a wasteful number, since it uses less digits than its factorization.

78728705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20248.

The product of its (nonzero) digits is 219520, while the sum is 44.

The square root of 78728705 is about 8872.9197562020. The cubic root of 78728705 is about 428.5923048825.

It can be divided in two parts, 787 and 28705, that added together give a palindrome (29492).

The spelling of 78728705 in words is "seventy-eight million, seven hundred twenty-eight thousand, seven hundred five".