16440023 has 4 divisors (see below), whose sum is σ = 16569600. Its totient is φ = 16310448.

The previous prime is 16440019. The next prime is 16440029. The reversal of 16440023 is 32004461.

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: 32004461 = 4639 ⋅6899.

It is a cyclic number.

It is not a de Polignac number, because 16440023 - 2² = 16440019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16439977 and 16440004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16440029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64598 + ... + 64851.

It is an arithmetic number, because the mean of its divisors is an integer number (4142400).

Almost surely, 2^16440023 is an apocalyptic number.

16440023 is a deficient number, since it is larger than the sum of its proper divisors (129577).

16440023 is a wasteful number, since it uses less digits than its factorization.

16440023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129576.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 16440023 is about 4054.6298228075. The cubic root of 16440023 is about 254.2733278154.

Adding to 16440023 its reverse (32004461), we get a palindrome (48444484).

The spelling of 16440023 in words is "sixteen million, four hundred forty thousand, twenty-three".