19866798 has 48 divisors (see below), whose sum is σ = 50899680. Its totient is φ = 5479488.

The previous prime is 19866793. The next prime is 19866823. The reversal of 19866798 is 89766891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19866793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 936 + ... + 6372.

It is an arithmetic number, because the mean of its divisors is an integer number (1060410).

Almost surely, 2^19866798 is an apocalyptic number.

19866798 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19866798, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25449840).

19866798 is an abundant number, since it is smaller than the sum of its proper divisors (31032882).

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

19866798 is a wasteful number, since it uses less digits than its factorization.

19866798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5481 (or 5478 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The square root of 19866798 is about 4457.2186394656. The cubic root of 19866798 is about 270.8378091147.

It can be divided in two parts, 198667 and 98, that added together give a triangular number (198765 = T₆₃₀).

The spelling of 19866798 in words is "nineteen million, eight hundred sixty-six thousand, seven hundred ninety-eight".