16670321 has 2 divisors, whose sum is σ = 16670322. Its totient is φ = 16670320.

The previous prime is 16670317. The next prime is 16670327. The reversal of 16670321 is 12307661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15840400 + 829921 = 3980^2 + 911^2 .

It is an emirp because it is prime and its reverse (12307661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16670321 - 2² = 16670317 is a prime.

It is not a weakly prime, because it can be changed into another prime (16670327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8335160 + 8335161.

It is an arithmetic number, because the mean of its divisors is an integer number (8335161).

Almost surely, 2^16670321 is an apocalyptic number.

It is an amenable number.

16670321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16670321 is an equidigital number, since it uses as much as digits as its factorization.

16670321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 16670321 is about 4082.9304427090. The cubic root of 16670321 is about 255.4551451009.

Adding to 16670321 its reverse (12307661), we get a palindrome (28977982).

The spelling of 16670321 in words is "sixteen million, six hundred seventy thousand, three hundred twenty-one".