16440001 has 4 divisors (see below), whose sum is σ = 16457904. Its totient is φ = 16422100.

The previous prime is 16439999. The next prime is 16440007. The reversal of 16440001 is 10004461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16440001 - 2¹ = 16439999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16440007) 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, 7495 + ... + 9436.

It is an arithmetic number, because the mean of its divisors is an integer number (4114476).

Almost surely, 2^16440001 is an apocalyptic number.

It is an amenable number.

16440001 is a deficient number, since it is larger than the sum of its proper divisors (17903).

16440001 is an equidigital number, since it uses as much as digits as its factorization.

16440001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17902.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 16440001 is about 4054.6271098586. The cubic root of 16440001 is about 254.2732143927.

Adding to 16440001 its reverse (10004461), we get a palindrome (26444462).

The spelling of 16440001 in words is "sixteen million, four hundred forty thousand, one".