78785191971 has 24 divisors (see below), whose sum is σ = 118034489664. Its totient is φ = 52515089640.

The previous prime is 78785191889. The next prime is 78785191973. The reversal of 78785191971 is 17919158787.

It is not a de Polignac number, because 78785191971 - 2¹⁰ = 78785190947 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78785191899 and 78785191908.

It is not an unprimeable number, because it can be changed into a prime (78785191973) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1753416 + ... + 1797786.

It is an arithmetic number, because the mean of its divisors is an integer number (4918103736).

Almost surely, 2^78785191971 is an apocalyptic number.

78785191971 is a deficient number, since it is larger than the sum of its proper divisors (39249297693).

78785191971 is an equidigital number, since it uses as much as digits as its factorization.

78785191971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51693 (or 51681 counting only the distinct ones).

The product of its digits is 8890560, while the sum is 63.

The spelling of 78785191971 in words is "seventy-eight billion, seven hundred eighty-five million, one hundred ninety-one thousand, nine hundred seventy-one".