78814386121 has 9 divisors (see below), whose sum is σ = 79128656679. Its totient is φ = 78501362136.

The previous prime is 78814386089. The next prime is 78814386139. The reversal of 78814386121 is 12168341887.

The square root of 78814386121 is 280739.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 77103405625 + 1710980496 = 277675^2 + 41364^2 .

It is not a de Polignac number, because 78814386121 - 2⁵ = 78814386089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78814366121) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 107522671 + ... + 107523403.

Almost surely, 2^78814386121 is an apocalyptic number.

78814386121 is the 280739-th square number.

78814386121 is the 140370-th centered octagonal number.

It is an amenable number.

78814386121 is a deficient number, since it is larger than the sum of its proper divisors (314270558).

78814386121 is an frugal number, since it uses more digits than its factorization.

78814386121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232 (or 1116 counting only the distinct ones).

The product of its digits is 516096, while the sum is 49.

Multiplying 78814386121 by its sum of digits (49), we get a square (3861904919929 = 1965173²).

The spelling of 78814386121 in words is "seventy-eight billion, eight hundred fourteen million, three hundred eighty-six thousand, one hundred twenty-one".