21202023221 has 8 divisors (see below), whose sum is σ = 23087503200. Its totient is φ = 19393501680.

The previous prime is 21202023179. The next prime is 21202023233. The reversal of 21202023221 is 12232020212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21202023221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21202023221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202023251) 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, 19239035 + ... + 19240136.

It is an arithmetic number, because the mean of its divisors is an integer number (2885937900).

Almost surely, 2^21202023221 is an apocalyptic number.

It is an amenable number.

21202023221 is a deficient number, since it is larger than the sum of its proper divisors (1885479979).

21202023221 is a wasteful number, since it uses less digits than its factorization.

21202023221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38479219.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21202023221 its reverse (12232020212), we get a palindrome (33434043433).

The spelling of 21202023221 in words is "twenty-one billion, two hundred two million, twenty-three thousand, two hundred twenty-one".