16421218 has 48 divisors (see below), whose sum is σ = 30100896. Its totient is φ = 6638720.

The previous prime is 16421213. The next prime is 16421233. The reversal of 16421218 is 81212461.

16421218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 16421192 and 16421201.

It is not an unprimeable number, because it can be changed into a prime (16421213) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 197805 + ... + 197887.

It is an arithmetic number, because the mean of its divisors is an integer number (627102).

Almost surely, 2^16421218 is an apocalyptic number.

16421218 is a deficient number, since it is larger than the sum of its proper divisors (13679678).

16421218 is a wasteful number, since it uses less digits than its factorization.

16421218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 136 counting only the distinct ones).

The product of its digits is 768, while the sum is 25.

The square root of 16421218 is about 4052.3102053026. The cubic root of 16421218 is about 254.1763402332.

Adding to 16421218 its reverse (81212461), we get a palindrome (97633679).

The spelling of 16421218 in words is "sixteen million, four hundred twenty-one thousand, two hundred eighteen".