78644357858 has 32 divisors (see below), whose sum is σ = 129137448960. Its totient is φ = 35623521360.

The previous prime is 78644357843. The next prime is 78644357881. The reversal of 78644357858 is 85875344687.

It is a junction number, because it is equal to n+sod(n) for n = 78644357794 and 78644357803.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12395435 + ... + 12401777.

It is an arithmetic number, because the mean of its divisors is an integer number (4035545280).

Almost surely, 2^78644357858 is an apocalyptic number.

78644357858 is a deficient number, since it is larger than the sum of its proper divisors (50493091102).

78644357858 is a wasteful number, since it uses less digits than its factorization.

78644357858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8222.

The product of its digits is 180633600, while the sum is 65.

The spelling of 78644357858 in words is "seventy-eight billion, six hundred forty-four million, three hundred fifty-seven thousand, eight hundred fifty-eight".