1213312221 has 48 divisors (see below), whose sum is σ = 1966543488. Its totient is φ = 714470400.

The previous prime is 1213312207. The next prime is 1213312249. The reversal of 1213312221 is 1222133121.

It is not a de Polignac number, because 1213312221 - 2⁶ = 1213312157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1213312194 and 1213312203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213312921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1367440 + ... + 1368326.

It is an arithmetic number, because the mean of its divisors is an integer number (40969656).

Almost surely, 2^1213312221 is an apocalyptic number.

1213312221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1213312221 is a deficient number, since it is larger than the sum of its proper divisors (753231267).

1213312221 is a wasteful number, since it uses less digits than its factorization.

1213312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282 (or 1279 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1213312221 is about 34832.6315543342. The cubic root of 1213312221 is about 1066.5736677492.

Adding to 1213312221 its reverse (1222133121), we get a palindrome (2435445342).

Subtracting 1213312221 from its reverse (1222133121), we obtain a square (8820900 = 2970²).

The spelling of 1213312221 in words is "one billion, two hundred thirteen million, three hundred twelve thousand, two hundred twenty-one".