78365640838969 has 9 divisors (see below), whose sum is σ = 86137546964581. Its totient is φ = 71241403147420.

The previous prime is 78365640838939. The next prime is 78365640839009. The reversal of 78365640838969 is 96983804656387.

The square root of 78365640838969 is 8852437.

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

It is not a de Polignac number, because 78365640838969 - 2¹¹ = 78365640836921 is a prime.

It is a super-2 number, since 2×78365640838969² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78365640838892 and 78365640838901.

It is not an unprimeable number, because it can be changed into a prime (78365640838909) 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, 96974424 + ... + 97779190.

Almost surely, 2^{78365640838969} is an apocalyptic number.

78365640838969 is the 8852437-th square number.

78365640838969 is the 4426219-th centered octagonal number.

It is an amenable number.

78365640838969 is a deficient number, since it is larger than the sum of its proper divisors (7771906125612).

78365640838969 is an frugal number, since it uses more digits than its factorization.

78365640838969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609556 (or 804778 counting only the distinct ones).

The product of its (nonzero) digits is 11287019520, while the sum is 82.

The spelling of 78365640838969 in words is "seventy-eight trillion, three hundred sixty-five billion, six hundred forty million, eight hundred thirty-eight thousand, nine hundred sixty-nine".