78398493877 has 6 divisors (see below), whose sum is σ = 86173551254. Its totient is φ = 71271357960.

The previous prime is 78398493857. The next prime is 78398493893. The reversal of 78398493877 is 77839489387.

It can be written as a sum of positive squares in only one way, i.e., 46431199441 + 31967294436 = 215479^2 + 178794^2 .

It is not a de Polignac number, because 78398493877 - 2¹⁹ = 78397969589 is a prime.

It is a super-2 number, since 2×78398493877² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78398493827) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 323960598 + ... + 323960839.

Almost surely, 2^78398493877 is an apocalyptic number.

It is an amenable number.

78398493877 is a deficient number, since it is larger than the sum of its proper divisors (7775057377).

78398493877 is a wasteful number, since it uses less digits than its factorization.

78398493877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647921459 (or 647921448 counting only the distinct ones).

The product of its digits is 512096256, while the sum is 73.

It can be divided in two parts, 78398 and 493877, that added together give a palindrome (572275).

The spelling of 78398493877 in words is "seventy-eight billion, three hundred ninety-eight million, four hundred ninety-three thousand, eight hundred seventy-seven".