16601009 has 4 divisors (see below), whose sum is σ = 17322816. Its totient is φ = 15879204.

The previous prime is 16600951. The next prime is 16601029. The reversal of 16601009 is 90010661.

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 16601009 - 2¹⁶ = 16535473 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 721783 = 16601009 / (1 + 6 + 6 + 0 + 1 + 0 + 0 + 9).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16601029) 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, 360869 + ... + 360914.

It is an arithmetic number, because the mean of its divisors is an integer number (4330704).

Almost surely, 2^16601009 is an apocalyptic number.

It is an amenable number.

16601009 is a deficient number, since it is larger than the sum of its proper divisors (721807).

16601009 is an equidigital number, since it uses as much as digits as its factorization.

16601009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721806.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 16601009 is about 4074.4335802661. The cubic root of 16601009 is about 255.1006087687.

The spelling of 16601009 in words is "sixteen million, six hundred one thousand, nine".