78399992058129 has 81 divisors (see below), whose sum is σ = 134610796510281. Its totient is φ = 43841916452880.

The previous prime is 78399992058109. The next prime is 78399992058173. The reversal of 78399992058129 is 92185029999387.

The square root of 78399992058129 is 8854377.

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

78399992058129 is a `hidden beast` number, since 7 + 8 + 3 + 9 + 9 + 9 + 9 + 2 + 0 + 581 + 29 = 666.

It is not a de Polignac number, because 78399992058129 - 2⁹ = 78399992057617 is a prime.

It is a super-2 number, since 2×78399992058129² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78399992058109) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 8739265614 + ... + 8739274584.

Almost surely, 2^{78399992058129} is an apocalyptic number.

78399992058129 is the 8854377-th square number.

78399992058129 is the 4427189-th centered octagonal number.

It is an amenable number.

78399992058129 is a deficient number, since it is larger than the sum of its proper divisors (56210804452152).

78399992058129 is an frugal number, since it uses more digits than its factorization.

78399992058129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18056 (or 9028 counting only the distinct ones).

The product of its (nonzero) digits is 1587237120, while the sum is 81.

The spelling of 78399992058129 in words is "seventy-eight trillion, three hundred ninety-nine billion, nine hundred ninety-two million, fifty-eight thousand, one hundred twenty-nine".