19860816 has 40 divisors (see below), whose sum is σ = 52184160. Its totient is φ = 6507136.

The previous prime is 19860803. The next prime is 19860881. The reversal of 19860816 is 61806891.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 675 + ... + 6338.

It is an arithmetic number, because the mean of its divisors is an integer number (1304604).

Almost surely, 2^19860816 is an apocalyptic number.

19860816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19860816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26092080).

19860816 is an abundant number, since it is smaller than the sum of its proper divisors (32323344).

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

19860816 is a wasteful number, since it uses less digits than its factorization.

19860816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7083 (or 7077 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 19860816 is about 4456.5475426612. The cubic root of 19860816 is about 270.8106228110.

The spelling of 19860816 in words is "nineteen million, eight hundred sixty thousand, eight hundred sixteen".