21222003153621 has 16 divisors (see below), whose sum is σ = 29303921174528. Its totient is φ = 13647016825200.

The previous prime is 21222003153551. The next prime is 21222003153667. The reversal of 21222003153621 is 12635130022212.

It is not a de Polignac number, because 21222003153621 - 2⁴² = 16823956642517 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 (21222003153121) 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, 371622235 + ... + 371679336.

It is an arithmetic number, because the mean of its divisors is an integer number (1831495073408).

Almost surely, 2^{21222003153621} is an apocalyptic number.

It is an amenable number.

21222003153621 is a deficient number, since it is larger than the sum of its proper divisors (8081918020907).

21222003153621 is a wasteful number, since it uses less digits than its factorization.

21222003153621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743301912.

The product of its (nonzero) digits is 8640, while the sum is 30.

Adding to 21222003153621 its reverse (12635130022212), we get a palindrome (33857133175833).

The spelling of 21222003153621 in words is "twenty-one trillion, two hundred twenty-two billion, three million, one hundred fifty-three thousand, six hundred twenty-one".