78491852221778 has 16 divisors (see below), whose sum is σ = 120344652042624. Its totient is φ = 38378382299280.

The previous prime is 78491852221703. The next prime is 78491852221799. The reversal of 78491852221778 is 87712225819487.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353411300 + ... + 353633327.

It is an arithmetic number, because the mean of its divisors is an integer number (7521540752664).

Almost surely, 2^{78491852221778} is an apocalyptic number.

78491852221778 is a deficient number, since it is larger than the sum of its proper divisors (41852799820846).

78491852221778 is a wasteful number, since it uses less digits than its factorization.

78491852221778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707045857.

The product of its digits is 252887040, while the sum is 71.

The spelling of 78491852221778 in words is "seventy-eight trillion, four hundred ninety-one billion, eight hundred fifty-two million, two hundred twenty-one thousand, seven hundred seventy-eight".