78997877775 has 48 divisors (see below), whose sum is σ = 145810072320. Its totient is φ = 41932447200.

The previous prime is 78997877771. The next prime is 78997877839. The reversal of 78997877775 is 57777879987.

It is not a de Polignac number, because 78997877775 - 2² = 78997877771 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78997877694 and 78997877703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78997877771) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 134907 + ... + 419756.

It is an arithmetic number, because the mean of its divisors is an integer number (3037709840).

Almost surely, 2^78997877775 is an apocalyptic number.

78997877775 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

78997877775 is a deficient number, since it is larger than the sum of its proper divisors (66812194545).

78997877775 is a wasteful number, since it uses less digits than its factorization.

78997877775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554893 (or 554882 counting only the distinct ones).

The product of its digits is 3049462080, while the sum is 81.

The spelling of 78997877775 in words is "seventy-eight billion, nine hundred ninety-seven million, eight hundred seventy-seven thousand, seven hundred seventy-five".