21002001220201 has 4 divisors (see below), whose sum is σ = 21002018664592. Its totient is φ = 21001983775812.

The previous prime is 21002001220121. The next prime is 21002001220217. The reversal of 21002001220201 is 10202210020012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21002001220201 - 2²⁹ = 21001464349289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002001230201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6770751 + ... + 9372676.

It is an arithmetic number, because the mean of its divisors is an integer number (5250504666148).

Almost surely, 2^{21002001220201} is an apocalyptic number.

It is an amenable number.

21002001220201 is a deficient number, since it is larger than the sum of its proper divisors (17444391).

21002001220201 is a wasteful number, since it uses less digits than its factorization.

21002001220201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17444390.

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

Adding to 21002001220201 its reverse (10202210020012), we get a palindrome (31204211240213).

The spelling of 21002001220201 in words is "twenty-one trillion, two billion, one million, two hundred twenty thousand, two hundred one".