21221020221001 has 32 divisors (see below), whose sum is σ = 22736828252160. Its totient is φ = 19763423222400.

The previous prime is 21221020220969. The next prime is 21221020221061. The reversal of 21221020221001 is 10012202012212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21221020221001 - 2⁵ = 21221020220969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221020221061) 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, 41757690 + ... + 42262828.

It is an arithmetic number, because the mean of its divisors is an integer number (710525882880).

Almost surely, 2^{21221020221001} is an apocalyptic number.

It is an amenable number.

21221020221001 is a deficient number, since it is larger than the sum of its proper divisors (1515808031159).

21221020221001 is a wasteful number, since it uses less digits than its factorization.

21221020221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505557.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221020221001 its reverse (10012202012212), we get a palindrome (31233222233213).

The spelling of 21221020221001 in words is "twenty-one trillion, two hundred twenty-one billion, twenty million, two hundred twenty-one thousand, one".