16421223 has 36 divisors (see below), whose sum is σ = 27621288. Its totient is φ = 8648640.

The previous prime is 16421213. The next prime is 16421233. The reversal of 16421223 is 32212461.

It is an interprime number because it is at equal distance from previous prime (16421213) and next prime (16421233).

It is not a de Polignac number, because 16421223 - 2⁵ = 16421191 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 16421223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16421203) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 24513 + ... + 25173.

It is an arithmetic number, because the mean of its divisors is an integer number (767258).

Almost surely, 2^16421223 is an apocalyptic number.

16421223 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

16421223 is a deficient number, since it is larger than the sum of its proper divisors (11200065).

16421223 is a wasteful number, since it uses less digits than its factorization.

16421223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 704 (or 684 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 16421223 is about 4052.3108222346. The cubic root of 16421223 is about 254.1763660308.

Adding to 16421223 its reverse (32212461), we get a palindrome (48633684).

The spelling of 16421223 in words is "sixteen million, four hundred twenty-one thousand, two hundred twenty-three".