78785191969 has 81 divisors (see below), whose sum is σ = 98333338131. Its totient is φ = 63053527680.

The previous prime is 78785191889. The next prime is 78785191973. The reversal of 78785191969 is 96919158787.

The square root of 78785191969 is 280687.

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., 61337952225 + 17447239744 = 247665^2 + 132088^2 .

It is not a de Polignac number, because 78785191969 - 2¹⁷ = 78785060897 is a prime.

It is a super-2 number, since 2×78785191969² (a number of 23 digits) contains 22 as substring.

Its product of digits (68584320) is a multiple of the sum of its prime divisors (126).

It is a junction number, because it is equal to n+sod(n) for n = 78785191898 and 78785191907.

It is not an unprimeable number, because it can be changed into a prime (78785191469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 997280872 + ... + 997280950.

Almost surely, 2^78785191969 is an apocalyptic number.

78785191969 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

78785191969 is the 280687-th square number.

78785191969 is the 140344-th centered octagonal number.

It is an amenable number.

78785191969 is a deficient number, since it is larger than the sum of its proper divisors (19548146162).

78785191969 is a wasteful number, since it uses less digits than its factorization.

78785191969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 126 counting only the distinct ones).

The product of its digits is 68584320, while the sum is 70.

The spelling of 78785191969 in words is "seventy-eight billion, seven hundred eighty-five million, one hundred ninety-one thousand, nine hundred sixty-nine".