21607009 has 8 divisors (see below), whose sum is σ = 22920480. Its totient is φ = 20311200.

The previous prime is 21607007. The next prime is 21607013. The reversal of 21607009 is 90070612.

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 21607009 - 2¹ = 21607007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21607007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1852 + ... + 6829.

It is an arithmetic number, because the mean of its divisors is an integer number (2865060).

Almost surely, 2^21607009 is an apocalyptic number.

It is an amenable number.

21607009 is a deficient number, since it is larger than the sum of its proper divisors (1313471).

21607009 is a wasteful number, since it uses less digits than its factorization.

21607009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8831.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21607009 is about 4648.3340026293. The cubic root of 21607009 is about 278.5254498111.

The spelling of 21607009 in words is "twenty-one million, six hundred seven thousand, nine".