21221022352521 has 32 divisors (see below), whose sum is σ = 28634223052800. Its totient is φ = 13978630512000.

The previous prime is 21221022352507. The next prime is 21221022352589. The reversal of 21221022352521 is 12525322012212.

It is not a de Polignac number, because 21221022352521 - 2⁵ = 21221022352489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221022352121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 299523061 + ... + 299593901.

It is an arithmetic number, because the mean of its divisors is an integer number (894819470400).

Almost surely, 2^{21221022352521} is an apocalyptic number.

It is an amenable number.

21221022352521 is a deficient number, since it is larger than the sum of its proper divisors (7413200700279).

21221022352521 is a wasteful number, since it uses less digits than its factorization.

21221022352521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74517.

The product of its (nonzero) digits is 9600, while the sum is 30.

Adding to 21221022352521 its reverse (12525322012212), we get a palindrome (33746344364733).

The spelling of 21221022352521 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-two million, three hundred fifty-two thousand, five hundred twenty-one".