19778856 has 32 divisors (see below), whose sum is σ = 49788000. Its totient is φ = 6547520.

The previous prime is 19778849. The next prime is 19778861. The reversal of 19778856 is 65887791.

It is a junction number, because it is equal to n+sod(n) for n = 19778799 and 19778808.

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, 811 + ... + 6341.

It is an arithmetic number, because the mean of its divisors is an integer number (1555875).

Almost surely, 2^19778856 is an apocalyptic number.

It is an amenable number.

19778856 is an abundant number, since it is smaller than the sum of its proper divisors (30009144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19778856 is a wasteful number, since it uses less digits than its factorization.

19778856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5689 (or 5685 counting only the distinct ones).

The product of its digits is 846720, while the sum is 51.

The square root of 19778856 is about 4447.3425773151. The cubic root of 19778856 is about 270.4375894547.

The spelling of 19778856 in words is "nineteen million, seven hundred seventy-eight thousand, eight hundred fifty-six".