16121216 has 64 divisors (see below), whose sum is σ = 34333200. Its totient is φ = 7526400.

The previous prime is 16121207. The next prime is 16121221. The reversal of 16121216 is 61212161.

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

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159566 + ... + 159666.

Almost surely, 2^16121216 is an apocalyptic number.

16121216 is a gapful number since it is divisible by the number (16) 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 16121216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17166600).

16121216 is an abundant number, since it is smaller than the sum of its proper divisors (18211984).

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

16121216 is a wasteful number, since it uses less digits than its factorization.

16121216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 175 counting only the distinct ones).

The product of its digits is 144, while the sum is 20.

The square root of 16121216 is about 4015.1234103076. The cubic root of 16121216 is about 252.6189538525.

Adding to 16121216 its reverse (61212161), we get a palindrome (77333377).

The spelling of 16121216 in words is "sixteen million, one hundred twenty-one thousand, two hundred sixteen".