16243021 has 2 divisors, whose sum is σ = 16243022. Its totient is φ = 16243020.

The previous prime is 16243013. The next prime is 16243033. The reversal of 16243021 is 12034261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13793796 + 2449225 = 3714^2 + 1565^2 .

It is a cyclic number.

It is not a de Polignac number, because 16243021 - 2³ = 16243013 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16243021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16243061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8121510 + 8121511.

It is an arithmetic number, because the mean of its divisors is an integer number (8121511).

Almost surely, 2^16243021 is an apocalyptic number.

It is an amenable number.

16243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

16243021 is an equidigital number, since it uses as much as digits as its factorization.

16243021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 16243021 is about 4030.2631427737. The cubic root of 16243021 is about 253.2535850475.

Adding to 16243021 its reverse (12034261), we get a palindrome (28277282).

The spelling of 16243021 in words is "sixteen million, two hundred forty-three thousand, twenty-one".