16700221 has 6 divisors (see below), whose sum is σ = 17625822. Its totient is φ = 15820920.

The previous prime is 16700207. The next prime is 16700251. The reversal of 16700221 is 12200761.

It can be written as a sum of positive squares in only one way, i.e., 16687225 + 12996 = 4085^2 + 114^2 .

It is not a de Polignac number, because 16700221 - 2¹¹ = 16698173 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16700251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22770 + ... + 23491.

It is an arithmetic number, because the mean of its divisors is an integer number (2937637).

Almost surely, 2^16700221 is an apocalyptic number.

It is an amenable number.

16700221 is a deficient number, since it is larger than the sum of its proper divisors (925601).

16700221 is an equidigital number, since it uses as much as digits as its factorization.

16700221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46299 (or 46280 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 16700221 is about 4086.5903880864. The cubic root of 16700221 is about 255.6077825695.

Adding to 16700221 its reverse (12200761), we get a palindrome (28900982).

The spelling of 16700221 in words is "sixteen million, seven hundred thousand, two hundred twenty-one".