16170421 has 4 divisors (see below), whose sum is σ = 16202700. Its totient is φ = 16138144.

The previous prime is 16170389. The next prime is 16170457. The reversal of 16170421 is 12407161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8820900 + 7349521 = 2970^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 16170421 - 2⁵ = 16170389 is a prime.

It is a super-2 number, since 2×16170421² = 522965030634482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16170392 and 16170401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16170461) 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 3 ways as a sum of consecutive naturals, for example, 15376 + ... + 16393.

It is an arithmetic number, because the mean of its divisors is an integer number (4050675).

Almost surely, 2^16170421 is an apocalyptic number.

It is an amenable number.

16170421 is a deficient number, since it is larger than the sum of its proper divisors (32279).

16170421 is an equidigital number, since it uses as much as digits as its factorization.

16170421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32278.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 16170421 is about 4021.2461998739. The cubic root of 16170421 is about 252.8757064174.

Adding to 16170421 its reverse (12407161), we get a palindrome (28577582).

The spelling of 16170421 in words is "sixteen million, one hundred seventy thousand, four hundred twenty-one".