10001221111 has 4 divisors (see below), whose sum is σ = 11429966992. Its totient is φ = 8572475232.

The previous prime is 10001221103. The next prime is 10001221127. The reversal of 10001221111 is 11112210001.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 10001221111 - 2³ = 10001221103 is a prime.

It is a super-2 number, since 2×10001221111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10001221141) 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, 714372930 + ... + 714372943.

It is an arithmetic number, because the mean of its divisors is an integer number (2857491748).

Almost surely, 2^10001221111 is an apocalyptic number.

10001221111 is a deficient number, since it is larger than the sum of its proper divisors (1428745881).

10001221111 is an equidigital number, since it uses as much as digits as its factorization.

10001221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1428745880.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 10001221111 its reverse (11112210001), we get a palindrome (21113431112).

The spelling of 10001221111 in words is "ten billion, one million, two hundred twenty-one thousand, one hundred eleven".