21223212009 has 8 divisors (see below), whose sum is σ = 28696174272. Its totient is φ = 13949528880.

The previous prime is 21223212001. The next prime is 21223212011. The reversal of 21223212009 is 90021232212.

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

It is not a de Polignac number, because 21223212009 - 2³ = 21223212001 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21223212009.

It is not an unprimeable number, because it can be changed into a prime (21223212001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49819534 + ... + 49819959.

It is an arithmetic number, because the mean of its divisors is an integer number (3587021784).

Almost surely, 2^21223212009 is an apocalyptic number.

It is an amenable number.

21223212009 is a deficient number, since it is larger than the sum of its proper divisors (7472962263).

21223212009 is an equidigital number, since it uses as much as digits as its factorization.

21223212009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99639567.

The product of its (nonzero) digits is 864, while the sum is 24.

The spelling of 21223212009 in words is "twenty-one billion, two hundred twenty-three million, two hundred twelve thousand, nine".