16238561 has 4 divisors (see below), whose sum is σ = 16258452. Its totient is φ = 16218672.

The previous prime is 16238543. The next prime is 16238567. The reversal of 16238561 is 16583261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16583261 = 173 ⋅95857.

It can be written as a sum of positive squares in 2 ways, for example, as 398161 + 15840400 = 631^2 + 3980^2 .

It is a cyclic number.

It is not a de Polignac number, because 16238561 - 2¹⁸ = 15976417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16238567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8666 + ... + 10371.

It is an arithmetic number, because the mean of its divisors is an integer number (4064613).

Almost surely, 2^16238561 is an apocalyptic number.

It is an amenable number.

16238561 is a deficient number, since it is larger than the sum of its proper divisors (19891).

16238561 is an equidigital number, since it uses as much as digits as its factorization.

16238561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19890.

The product of its digits is 8640, while the sum is 32.

The square root of 16238561 is about 4029.7097910395. The cubic root of 16238561 is about 253.2304035144.

The spelling of 16238561 in words is "sixteen million, two hundred thirty-eight thousand, five hundred sixty-one".