16404640 has 96 divisors (see below), whose sum is σ = 45045504. Its totient is φ = 5529600.

The previous prime is 16404637. The next prime is 16404649. The reversal of 16404640 is 4640461.

It is a super-2 number, since 2×16404640² = 538224427059200, which contains 22 as substring.

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (16404649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108565 + ... + 108715.

It is an arithmetic number, because the mean of its divisors is an integer number (469224).

Almost surely, 2^16404640 is an apocalyptic number.

16404640 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 16404640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22522752).

16404640 is an abundant number, since it is smaller than the sum of its proper divisors (28640864).

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

16404640 is a wasteful number, since it uses less digits than its factorization.

16404640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 16404640 is about 4050.2641889141. The cubic root of 16404640 is about 254.0907770683.

The spelling of 16404640 in words is "sixteen million, four hundred four thousand, six hundred forty".