10211201221 has 8 divisors (see below), whose sum is σ = 11061749720. Its totient is φ = 9425722176.

The previous prime is 10211201177. The next prime is 10211201239. The reversal of 10211201221 is 12210211201.

It can be written as a sum of positive squares in 4 ways, for example, as 2105800321 + 8105400900 = 45889^2 + 90030^2 .

It is not a de Polignac number, because 10211201221 - 2⁷ = 10211201093 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10211208221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2321700 + ... + 2326093.

It is an arithmetic number, because the mean of its divisors is an integer number (1382718715).

Almost surely, 2^10211201221 is an apocalyptic number.

It is an amenable number.

10211201221 is a deficient number, since it is larger than the sum of its proper divisors (850548499).

10211201221 is an frugal number, since it uses more digits than its factorization.

10211201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4647832 (or 4647806 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 10211201221 its reverse (12210211201), we get a palindrome (22421412422).

The spelling of 10211201221 in words is "ten billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".