78919091987 has 8 divisors (see below), whose sum is σ = 82380335904. Its totient is φ = 75460346368.

The previous prime is 78919091983. The next prime is 78919092101.

78919091987 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78919091987 - 2² = 78919091983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78919091983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 559868 + ... + 686505.

It is an arithmetic number, because the mean of its divisors is an integer number (10297541988).

Almost surely, 2^78919091987 is an apocalyptic number.

78919091987 is a deficient number, since it is larger than the sum of its proper divisors (3461243917).

78919091987 is a wasteful number, since it uses less digits than its factorization.

78919091987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249149.

The product of its (nonzero) digits is 20575296, while the sum is 68.

The spelling of 78919091987 in words is "seventy-eight billion, nine hundred nineteen million, ninety-one thousand, nine hundred eighty-seven".