21500669209 has 16 divisors (see below), whose sum is σ = 22483802880. Its totient is φ = 20540096640.

The previous prime is 21500669191. The next prime is 21500669227. The reversal of 21500669209 is 90296600512.

It is an interprime number because it is at equal distance from previous prime (21500669191) and next prime (21500669227).

It is a cyclic number.

It is not a de Polignac number, because 21500669209 - 2⁷ = 21500669081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21500669299) 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 15 ways as a sum of consecutive naturals, for example, 4324477 + ... + 4329445.

It is an arithmetic number, because the mean of its divisors is an integer number (1405237680).

Almost surely, 2^21500669209 is an apocalyptic number.

It is an amenable number.

21500669209 is a deficient number, since it is larger than the sum of its proper divisors (983133671).

21500669209 is a wasteful number, since it uses less digits than its factorization.

21500669209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7200.

The product of its (nonzero) digits is 58320, while the sum is 40.

The spelling of 21500669209 in words is "twenty-one billion, five hundred million, six hundred sixty-nine thousand, two hundred nine".