78984695991 has 16 divisors (see below), whose sum is σ = 110089096704. Its totient is φ = 50276602464.

The previous prime is 78984695903. The next prime is 78984696023. The reversal of 78984695991 is 19959648987.

It is not a de Polignac number, because 78984695991 - 2⁹ = 78984695479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78984695891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 989131 + ... + 1065996.

It is an arithmetic number, because the mean of its divisors is an integer number (6880568544).

Almost surely, 2^78984695991 is an apocalyptic number.

78984695991 is a deficient number, since it is larger than the sum of its proper divisors (31104400713).

78984695991 is a wasteful number, since it uses less digits than its factorization.

78984695991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2055710.

The product of its digits is 352719360, while the sum is 75.

The spelling of 78984695991 in words is "seventy-eight billion, nine hundred eighty-four million, six hundred ninety-five thousand, nine hundred ninety-one".