16421004 has 36 divisors (see below), whose sum is σ = 41637960. Its totient is φ = 5456640.

The previous prime is 16420961. The next prime is 16421023. The reversal of 16421004 is 40012461.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17212 + ... + 18140.

It is an arithmetic number, because the mean of its divisors is an integer number (1156610).

Almost surely, 2^16421004 is an apocalyptic number.

It is an amenable number.

16421004 is an abundant number, since it is smaller than the sum of its proper divisors (25216956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16421004 is a wasteful number, since it uses less digits than its factorization.

16421004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1430 (or 1425 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 16421004 is about 4052.2838005253. The cubic root of 16421004 is about 254.1752360932.

Adding to 16421004 its reverse (40012461), we get a palindrome (56433465).

The spelling of 16421004 in words is "sixteen million, four hundred twenty-one thousand, four".