11212312221 has 128 divisors (see below), whose sum is σ = 19377684480. Its totient is φ = 6344049600.

The previous prime is 11212312213. The next prime is 11212312229. The reversal of 11212312221 is 12221321211.

It is an interprime number because it is at equal distance from previous prime (11212312213) and next prime (11212312229).

It is not a de Polignac number, because 11212312221 - 2³ = 11212312213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11212312194 and 11212312203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11212312229) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 50279316 + ... + 50279538.

It is an arithmetic number, because the mean of its divisors is an integer number (151388160).

Almost surely, 2^11212312221 is an apocalyptic number.

11212312221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11212312221 is a deficient number, since it is larger than the sum of its proper divisors (8165372259).

11212312221 is a wasteful number, since it uses less digits than its factorization.

11212312221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444 (or 438 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 11212312221 its reverse (12221321211), we get a palindrome (23433633432).

The spelling of 11212312221 in words is "eleven billion, two hundred twelve million, three hundred twelve thousand, two hundred twenty-one".