16819840 has 64 divisors (see below), whose sum is σ = 41254920. Its totient is φ = 6553600.

The previous prime is 16819823. The next prime is 16819841. The reversal of 16819840 is 4891861.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12787776 + 4032064 = 3576^2 + 2008^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 16819840.

It is not an unprimeable number, because it can be changed into a prime (16819841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25920 + ... + 26560.

Almost surely, 2^16819840 is an apocalyptic number.

16819840 is a gapful number since it is divisible by the number (10) 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 16819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20627460).

16819840 is an abundant number, since it is smaller than the sum of its proper divisors (24435080).

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

16819840 is an equidigital number, since it uses as much as digits as its factorization.

16819840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701 (or 689 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 16819840 is about 4101.1998244416. The cubic root of 16819840 is about 256.2166135365.

The spelling of 16819840 in words is "sixteen million, eight hundred nineteen thousand, eight hundred forty".