16406009 has 4 divisors (see below), whose sum is σ = 16613760. Its totient is φ = 16198260.

The previous prime is 16405997. The next prime is 16406017. The reversal of 16406009 is 90060461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90060461 = 61 ⋅1476401.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16406009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16426009) 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, 103757 + ... + 103914.

It is an arithmetic number, because the mean of its divisors is an integer number (4153440).

Almost surely, 2^16406009 is an apocalyptic number.

It is an amenable number.

16406009 is a deficient number, since it is larger than the sum of its proper divisors (207751).

16406009 is an equidigital number, since it uses as much as digits as its factorization.

16406009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207750.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 16406009 is about 4050.4331867098. The cubic root of 16406009 is about 254.0978449994.

The spelling of 16406009 in words is "sixteen million, four hundred six thousand, nine".