78727721216 has 18 divisors (see below), whose sum is σ = 157147912782. Its totient is φ = 39363860480.

The previous prime is 78727721183. The next prime is 78727721231. The reversal of 78727721216 is 61212772787.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 42475561216 + 36252160000 = 206096^2 + 190400^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 153764825 + ... + 153765336.

It is an arithmetic number, because the mean of its divisors is an integer number (8730439599).

Almost surely, 2^78727721216 is an apocalyptic number.

It is an amenable number.

78727721216 is a deficient number, since it is larger than the sum of its proper divisors (78420191566).

78727721216 is an equidigital number, since it uses as much as digits as its factorization.

78727721216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307530177 (or 307530163 counting only the distinct ones).

The product of its digits is 921984, while the sum is 50.

The spelling of 78727721216 in words is "seventy-eight billion, seven hundred twenty-seven million, seven hundred twenty-one thousand, two hundred sixteen".