16444391 has 4 divisors (see below), whose sum is σ = 16888872. Its totient is φ = 15999912.

The previous prime is 16444387. The next prime is 16444399. The reversal of 16444391 is 19344461.

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: 19344461 = 1597 ⋅12113.

It is a cyclic number.

It is not a de Polignac number, because 16444391 - 2² = 16444387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16444399) 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, 222185 + ... + 222258.

It is an arithmetic number, because the mean of its divisors is an integer number (4222218).

Almost surely, 2^16444391 is an apocalyptic number.

16444391 is a deficient number, since it is larger than the sum of its proper divisors (444481).

16444391 is an equidigital number, since it uses as much as digits as its factorization.

16444391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444480.

The product of its digits is 10368, while the sum is 32.

The square root of 16444391 is about 4055.1684305341. The cubic root of 16444391 is about 254.2958453740.

The spelling of 16444391 in words is "sixteen million, four hundred forty-four thousand, three hundred ninety-one".