19800450 has 60 divisors (see below), whose sum is σ = 55027170. Its totient is φ = 5279040.

The previous prime is 19800421. The next prime is 19800463. The reversal of 19800450 is 5400891.

It can be written as a sum of positive squares in 3 ways, for example, as 16329681 + 3470769 = 4041^2 + 1863^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 1606 + ... + 6494.

Almost surely, 2^19800450 is an apocalyptic number.

19800450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19800450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27513585).

19800450 is an abundant number, since it is smaller than the sum of its proper divisors (35226720).

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

19800450 is a wasteful number, since it uses less digits than its factorization.

19800450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4913 (or 4899 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 19800450 is about 4449.7696569598. The cubic root of 19800450 is about 270.5359723834.

The spelling of 19800450 in words is "nineteen million, eight hundred thousand, four hundred fifty".