21010220201 has 4 divisors (see below), whose sum is σ = 21012878592. Its totient is φ = 21007561812.

The previous prime is 21010220191. The next prime is 21010220213. The reversal of 21010220201 is 10202201012.

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 a de Polignac number, because none of the positive numbers 2^k-21010220201 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21010220221) 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, 1317305 + ... + 1333158.

It is an arithmetic number, because the mean of its divisors is an integer number (5253219648).

Almost surely, 2^21010220201 is an apocalyptic number.

It is an amenable number.

21010220201 is a deficient number, since it is larger than the sum of its proper divisors (2658391).

21010220201 is an equidigital number, since it uses as much as digits as its factorization.

21010220201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2658390.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21010220201 its reverse (10202201012), we get a palindrome (31212421213).

The spelling of 21010220201 in words is "twenty-one billion, ten million, two hundred twenty thousand, two hundred one".