78981683391 has 30 divisors (see below), whose sum is σ = 127758909960. Its totient is φ = 48604104432.

The previous prime is 78981683371. The next prime is 78981683393. The reversal of 78981683391 is 19338618987.

78981683391 is a `hidden beast` number, since 7 + 89 + 8 + 168 + 3 + 391 = 666.

It is not a de Polignac number, because 78981683391 - 2¹⁵ = 78981650623 is a prime.

It is a super-2 number, since 2×78981683391² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78981683393) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 2871171 + ... + 2898548.

It is an arithmetic number, because the mean of its divisors is an integer number (4258630332).

Almost surely, 2^78981683391 is an apocalyptic number.

78981683391 is a deficient number, since it is larger than the sum of its proper divisors (48777226569).

78981683391 is a wasteful number, since it uses less digits than its factorization.

78981683391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5769757 (or 5769735 counting only the distinct ones).

The product of its digits is 15676416, while the sum is 63.

The spelling of 78981683391 in words is "seventy-eight billion, nine hundred eighty-one million, six hundred eighty-three thousand, three hundred ninety-one".