78749665558 has 4 divisors (see below), whose sum is σ = 118124498340. Its totient is φ = 39374832778.

The previous prime is 78749665513. The next prime is 78749665571. The reversal of 78749665558 is 85556694787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85556694787 = 61 ⋅1402568767.

It is a super-3 number, since 3×78749665558³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19687416388 + ... + 19687416391.

It is an arithmetic number, because the mean of its divisors is an integer number (29531124585).

Almost surely, 2^78749665558 is an apocalyptic number.

78749665558 is a deficient number, since it is larger than the sum of its proper divisors (39374832782).

78749665558 is a wasteful number, since it uses less digits than its factorization.

78749665558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39374832781.

The product of its digits is 508032000, while the sum is 70.

The spelling of 78749665558 in words is "seventy-eight billion, seven hundred forty-nine million, six hundred sixty-five thousand, five hundred fifty-eight".