10111212221 has 4 divisors (see below), whose sum is σ = 11030413344. Its totient is φ = 9192011100.

The previous prime is 10111212211. The next prime is 10111212269. The reversal of 10111212221 is 12221211101.

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 10111212221 - 2³⁰ = 9037470397 is a prime.

It is a super-2 number, since 2×10111212221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10111212196 and 10111212205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10111212211) 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, 459600545 + ... + 459600566.

It is an arithmetic number, because the mean of its divisors is an integer number (2757603336).

Almost surely, 2^10111212221 is an apocalyptic number.

10111212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10111212221 is a deficient number, since it is larger than the sum of its proper divisors (919201123).

10111212221 is an equidigital number, since it uses as much as digits as its factorization.

10111212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919201122.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 10111212221 its reverse (12221211101), we get a palindrome (22332423322).

The spelling of 10111212221 in words is "ten billion, one hundred eleven million, two hundred twelve thousand, two hundred twenty-one".