78644140017 has 16 divisors (see below), whose sum is σ = 107002526400. Its totient is φ = 51364440000.

The previous prime is 78644140009. The next prime is 78644140021. The reversal of 78644140017 is 71004144687.

It is not a de Polignac number, because 78644140017 - 2³ = 78644140009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78644140067) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 810142 + ... + 902007.

It is an arithmetic number, because the mean of its divisors is an integer number (6687657900).

Almost surely, 2^78644140017 is an apocalyptic number.

It is an amenable number.

78644140017 is a deficient number, since it is larger than the sum of its proper divisors (28358386383).

78644140017 is a wasteful number, since it uses less digits than its factorization.

78644140017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712464.

The product of its (nonzero) digits is 150528, while the sum is 42.

The spelling of 78644140017 in words is "seventy-eight billion, six hundred forty-four million, one hundred forty thousand, seventeen".