21202221001 has 64 divisors (see below), whose sum is σ = 24881472000. Its totient is φ = 18030055680.

The previous prime is 21202220993. The next prime is 21202221017. The reversal of 21202221001 is 10012220212.

It is a happy number.

It is not a de Polignac number, because 21202221001 - 2³ = 21202220993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202221091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 194515735 + ... + 194515843.

It is an arithmetic number, because the mean of its divisors is an integer number (388773000).

Almost surely, 2^21202221001 is an apocalyptic number.

It is an amenable number.

21202221001 is a deficient number, since it is larger than the sum of its proper divisors (3679250999).

21202221001 is a wasteful number, since it uses less digits than its factorization.

21202221001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291 (or 265 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21202221001 its reverse (10012220212), we get a palindrome (31214441213).

The spelling of 21202221001 in words is "twenty-one billion, two hundred two million, two hundred twenty-one thousand, one".