78363971649 has 24 divisors (see below), whose sum is σ = 113429227392. Its totient is φ = 52133440320.

The previous prime is 78363971627. The next prime is 78363971683. The reversal of 78363971649 is 94617936387.

78363971649 is a `hidden beast` number, since 7 + 83 + 6 + 397 + 164 + 9 = 666.

It is not a de Polignac number, because 78363971649 - 2¹¹ = 78363969601 is a prime.

It is a super-2 number, since 2×78363971649² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78363971149) 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 23 ways as a sum of consecutive naturals, for example, 20442637 + ... + 20446469.

It is an arithmetic number, because the mean of its divisors is an integer number (4726217808).

Almost surely, 2^78363971649 is an apocalyptic number.

It is an amenable number.

78363971649 is a deficient number, since it is larger than the sum of its proper divisors (35065255743).

78363971649 is a wasteful number, since it uses less digits than its factorization.

78363971649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7997 (or 7994 counting only the distinct ones).

The product of its digits is 41150592, while the sum is 63.

The spelling of 78363971649 in words is "seventy-eight billion, three hundred sixty-three million, nine hundred seventy-one thousand, six hundred forty-nine".