21223504533221 has 16 divisors (see below), whose sum is σ = 22097747509248. Its totient is φ = 20361363044400.

The previous prime is 21223504533211. The next prime is 21223504533241. The reversal of 21223504533221 is 12233540532212.

It is a cyclic number.

It is not a de Polignac number, because 21223504533221 - 2⁴² = 16825458022117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223504533211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2994836 + ... + 7170498.

It is an arithmetic number, because the mean of its divisors is an integer number (1381109219328).

Almost surely, 2^{21223504533221} is an apocalyptic number.

It is an amenable number.

21223504533221 is a deficient number, since it is larger than the sum of its proper divisors (874242976027).

21223504533221 is a wasteful number, since it uses less digits than its factorization.

21223504533221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4177112.

The product of its (nonzero) digits is 86400, while the sum is 35.

The spelling of 21223504533221 in words is "twenty-one trillion, two hundred twenty-three billion, five hundred four million, five hundred thirty-three thousand, two hundred twenty-one".