16464221 has 4 divisors (see below), whose sum is σ = 16473600. Its totient is φ = 16454844.

The previous prime is 16464187. The next prime is 16464229. The reversal of 16464221 is 12246461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 16464221 - 2⁶ = 16464157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16464229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1181 + ... + 5858.

It is an arithmetic number, because the mean of its divisors is an integer number (4118400).

Almost surely, 2^16464221 is an apocalyptic number.

It is an amenable number.

16464221 is a deficient number, since it is larger than the sum of its proper divisors (9379).

16464221 is an equidigital number, since it uses as much as digits as its factorization.

16464221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9378.

The product of its digits is 2304, while the sum is 26.

The square root of 16464221 is about 4057.6127217861. The cubic root of 16464221 is about 254.3980212671.

The spelling of 16464221 in words is "sixteen million, four hundred sixty-four thousand, two hundred twenty-one".