16313221 has 2 divisors, whose sum is σ = 16313222. Its totient is φ = 16313220.

The previous prime is 16313207. The next prime is 16313287. The reversal of 16313221 is 12231361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12744900 + 3568321 = 3570^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 16313221 - 2¹¹ = 16311173 is a prime.

It is a super-2 number, since 2×16313221² = 532242358789682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16313021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8156610 + 8156611.

It is an arithmetic number, because the mean of its divisors is an integer number (8156611).

Almost surely, 2^16313221 is an apocalyptic number.

It is an amenable number.

16313221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16313221 is an equidigital number, since it uses as much as digits as its factorization.

16313221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 16313221 is about 4038.9628619238. The cubic root of 16313221 is about 253.6179025615.

Adding to 16313221 its reverse (12231361), we get a palindrome (28544582).

The spelling of 16313221 in words is "sixteen million, three hundred thirteen thousand, two hundred twenty-one".