16221408 has 96 divisors (see below), whose sum is σ = 49351680. Its totient is φ = 4569600.

The previous prime is 16221391. The next prime is 16221431. The reversal of 16221408 is 80412261.

16221408 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

16221408 is a Rhonda number in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67753 + ... + 67991.

It is an arithmetic number, because the mean of its divisors is an integer number (514080).

Almost surely, 2^16221408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16221408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24675840).

16221408 is an abundant number, since it is smaller than the sum of its proper divisors (33130272).

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

16221408 is a wasteful number, since it uses less digits than its factorization.

16221408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360 (or 352 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 16221408 is about 4027.5809116640. The cubic root of 16221408 is about 253.1412085948.

Adding to 16221408 its reverse (80412261), we get a palindrome (96633669).

The spelling of 16221408 in words is "sixteen million, two hundred twenty-one thousand, four hundred eight".