16590421 has 2 divisors, whose sum is σ = 16590422. Its totient is φ = 16590420.

The previous prime is 16590403. The next prime is 16590433. The reversal of 16590421 is 12409561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12744900 + 3845521 = 3570^2 + 1961^2 .

It is an emirp because it is prime and its reverse (12409561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16590421 - 2¹¹ = 16588373 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 16590421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16594421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8295210 + 8295211.

It is an arithmetic number, because the mean of its divisors is an integer number (8295211).

Almost surely, 2^16590421 is an apocalyptic number.

It is an amenable number.

16590421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16590421 is an equidigital number, since it uses as much as digits as its factorization.

16590421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 16590421 is about 4073.1340513172. The cubic root of 16590421 is about 255.0463634780.

Adding to 16590421 its reverse (12409561), we get a palindrome (28999982).

The spelling of 16590421 in words is "sixteen million, five hundred ninety thousand, four hundred twenty-one".