16225621 has 2 divisors, whose sum is σ = 16225622. Its totient is φ = 16225620.

The previous prime is 16225613. The next prime is 16225681. The reversal of 16225621 is 12652261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15563025 + 662596 = 3945^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 16225621 - 2³ = 16225613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16225681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8112810 + 8112811.

It is an arithmetic number, because the mean of its divisors is an integer number (8112811).

Almost surely, 2^16225621 is an apocalyptic number.

It is an amenable number.

16225621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16225621 is an equidigital number, since it uses as much as digits as its factorization.

16225621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 16225621 is about 4028.1038963761. The cubic root of 16225621 is about 253.1631218507.

Adding to 16225621 its reverse (12652261), we get a palindrome (28877882).

The spelling of 16225621 in words is "sixteen million, two hundred twenty-five thousand, six hundred twenty-one".