16623440 has 40 divisors (see below), whose sum is σ = 39902208. Its totient is φ = 6433920.

The previous prime is 16623419. The next prime is 16623449. The reversal of 16623440 is 4432661.

It is a tau number, because it is divible by the number of its divisors (40).

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16623449) 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, 872 + ... + 5831.

Almost surely, 2^16623440 is an apocalyptic number.

16623440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16623440 is an abundant number, since it is smaller than the sum of its proper divisors (23278768).

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

16623440 is a wasteful number, since it uses less digits than its factorization.

16623440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6747 (or 6741 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 16623440 is about 4077.1853036133. The cubic root of 16623440 is about 255.2154529218.

The spelling of 16623440 in words is "sixteen million, six hundred twenty-three thousand, four hundred forty".