78749665557 has 8 divisors (see below), whose sum is σ = 105006293376. Its totient is φ = 52496407392.

The previous prime is 78749665513. The next prime is 78749665571. The reversal of 78749665557 is 75556694787.

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

It is not a de Polignac number, because 78749665557 - 2⁷ = 78749665429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78749665491 and 78749665500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78749665157) 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, 787368 + ... + 881729.

It is an arithmetic number, because the mean of its divisors is an integer number (13125786672).

Almost surely, 2^78749665557 is an apocalyptic number.

It is an amenable number.

78749665557 is a deficient number, since it is larger than the sum of its proper divisors (26256627819).

78749665557 is a wasteful number, since it uses less digits than its factorization.

78749665557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1684827.

The product of its digits is 444528000, while the sum is 69.

The spelling of 78749665557 in words is "seventy-eight billion, seven hundred forty-nine million, six hundred sixty-five thousand, five hundred fifty-seven".