16402009 has 8 divisors (see below), whose sum is σ = 18095112. Its totient is φ = 14770560.

The previous prime is 16402003. The next prime is 16402019. The reversal of 16402009 is 90020461.

It can be written as a sum of positive squares in 4 ways, for example, as 1617984 + 14784025 = 1272^2 + 3845^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16402009 - 2⁵ = 16401977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16402003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14854 + ... + 15919.

It is an arithmetic number, because the mean of its divisors is an integer number (2261889).

Almost surely, 2^16402009 is an apocalyptic number.

It is an amenable number.

16402009 is a deficient number, since it is larger than the sum of its proper divisors (1693103).

16402009 is a wasteful number, since it uses less digits than its factorization.

16402009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30827.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 16402009 is about 4049.9393822624. The cubic root of 16402009 is about 254.0771925260.

The spelling of 16402009 in words is "sixteen million, four hundred two thousand, nine".