16650421 has 4 divisors (see below), whose sum is σ = 16673344. Its totient is φ = 16627500.

The previous prime is 16650397. The next prime is 16650433. The reversal of 16650421 is 12405661.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16650421 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 (16650451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10335 + ... + 11836.

It is an arithmetic number, because the mean of its divisors is an integer number (4168336).

Almost surely, 2^16650421 is an apocalyptic number.

It is an amenable number.

16650421 is a deficient number, since it is larger than the sum of its proper divisors (22923).

16650421 is an equidigital number, since it uses as much as digits as its factorization.

16650421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22922.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 16650421 is about 4080.4927398539. The cubic root of 16650421 is about 255.3534557665.

It can be divided in two parts, 16650 and 421, that added together give a palindrome (17071).

The spelling of 16650421 in words is "sixteen million, six hundred fifty thousand, four hundred twenty-one".