21533500450221 has 8 divisors (see below), whose sum is σ = 30222456772320. Its totient is φ = 13600105547472.

The previous prime is 21533500450193. The next prime is 21533500450243. The reversal of 21533500450221 is 12205400533512.

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

It is not a de Polignac number, because 21533500450221 - 2²⁵ = 21533466895789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533500450321) 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, 188890354770 + ... + 188890354883.

It is an arithmetic number, because the mean of its divisors is an integer number (3777807096540).

Almost surely, 2^{21533500450221} is an apocalyptic number.

It is an amenable number.

21533500450221 is a deficient number, since it is larger than the sum of its proper divisors (8688956322099).

21533500450221 is a wasteful number, since it uses less digits than its factorization.

21533500450221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377780709675.

The product of its (nonzero) digits is 36000, while the sum is 33.

Adding to 21533500450221 its reverse (12205400533512), we get a palindrome (33738900983733).

The spelling of 21533500450221 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred million, four hundred fifty thousand, two hundred twenty-one".