16221516 has 24 divisors (see below), whose sum is σ = 39842880. Its totient is φ = 5122512.

The previous prime is 16221493. The next prime is 16221523. The reversal of 16221516 is 61512261.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 35346 + ... + 35801.

It is an arithmetic number, because the mean of its divisors is an integer number (1660120).

Almost surely, 2^16221516 is an apocalyptic number.

It is an amenable number.

16221516 is an abundant number, since it is smaller than the sum of its proper divisors (23621364).

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

16221516 is a wasteful number, since it uses less digits than its factorization.

16221516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71173 (or 71171 counting only the distinct ones).

The product of its digits is 720, while the sum is 24.

The square root of 16221516 is about 4027.5943191935. The cubic root of 16221516 is about 253.1417703871.

Adding to 16221516 its reverse (61512261), we get a palindrome (77733777).

The spelling of 16221516 in words is "sixteen million, two hundred twenty-one thousand, five hundred sixteen".