16221028 has 6 divisors (see below), whose sum is σ = 28386806. Its totient is φ = 8110512.

The previous prime is 16221017. The next prime is 16221031. The reversal of 16221028 is 82012261.

It can be written as a sum of positive squares in only one way, i.e., 13235044 + 2985984 = 3638^2 + 1728^2 .

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 as a sum of consecutive naturals, namely, 2027625 + ... + 2027632.

Almost surely, 2^16221028 is an apocalyptic number.

It is an amenable number.

16221028 is a deficient number, since it is larger than the sum of its proper divisors (12165778).

16221028 is a wasteful number, since it uses less digits than its factorization.

16221028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4055261 (or 4055259 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 16221028 is about 4027.5337366681. The cubic root of 16221028 is about 253.1392318981.

Adding to 16221028 its reverse (82012261), we get a palindrome (98233289).

The spelling of 16221028 in words is "sixteen million, two hundred twenty-one thousand, twenty-eight".