78316806921 has 32 divisors (see below), whose sum is σ = 109930504320. Its totient is φ = 49527475200.

The previous prime is 78316806809. The next prime is 78316806923. The reversal of 78316806921 is 12960861387.

It is not a de Polignac number, because 78316806921 - 2¹⁵ = 78316774153 is a prime.

It is a super-3 number, since 3×78316806921³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (78316806923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1277041 + ... + 1336961.

It is an arithmetic number, because the mean of its divisors is an integer number (3435328260).

Almost surely, 2^78316806921 is an apocalyptic number.

It is an amenable number.

78316806921 is a deficient number, since it is larger than the sum of its proper divisors (31613697399).

78316806921 is a wasteful number, since it uses less digits than its factorization.

78316806921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60217.

The product of its (nonzero) digits is 870912, while the sum is 51.

The spelling of 78316806921 in words is "seventy-eight billion, three hundred sixteen million, eight hundred six thousand, nine hundred twenty-one".