16221647 has 16 divisors (see below), whose sum is σ = 18385920. Its totient is φ = 14200032.

The previous prime is 16221641. The next prime is 16221659. The reversal of 16221647 is 74612261.

It is a cyclic number.

It is not a de Polignac number, because 16221647 - 2⁸ = 16221391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16221641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67754 + ... + 67992.

It is an arithmetic number, because the mean of its divisors is an integer number (1149120).

Almost surely, 2^16221647 is an apocalyptic number.

16221647 is a deficient number, since it is larger than the sum of its proper divisors (2164273).

16221647 is a wasteful number, since it uses less digits than its factorization.

16221647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502.

The product of its digits is 4032, while the sum is 29.

The square root of 16221647 is about 4027.6105819704. The cubic root of 16221647 is about 253.1424518171.

The spelling of 16221647 in words is "sixteen million, two hundred twenty-one thousand, six hundred forty-seven".