16405844 has 36 divisors (see below), whose sum is σ = 35540064. Its totient is φ = 6488352.

The previous prime is 16405819. The next prime is 16405847. The reversal of 16405844 is 44850461.

It is a nialpdrome in base 4 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 16405844.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16405847) 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 11 ways as a sum of consecutive naturals, for example, 2999 + ... + 6465.

It is an arithmetic number, because the mean of its divisors is an integer number (987224).

Almost surely, 2^16405844 is an apocalyptic number.

16405844 is a gapful number since it is divisible by the number (14) 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 16405844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17770032).

16405844 is an abundant number, since it is smaller than the sum of its proper divisors (19134220).

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

16405844 is a wasteful number, since it uses less digits than its factorization.

16405844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3504 (or 3489 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 16405844 is about 4050.4128184668. The cubic root of 16405844 is about 254.0969931513.

The spelling of 16405844 in words is "sixteen million, four hundred five thousand, eight hundred forty-four".