1211212312321 has 4 divisors (see below), whose sum is σ = 1321322522544. Its totient is φ = 1101102102100.

The previous prime is 1211212312231. The next prime is 1211212312327. The reversal of 1211212312321 is 1232132121121.

It is a happy number.

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 de Polignac number, because none of the positive numbers 2^k-1211212312321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211212312292 and 1211212312301.

It is not an unprimeable number, because it can be changed into a prime (1211212312327) 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, 55055105095 + ... + 55055105116.

It is an arithmetic number, because the mean of its divisors is an integer number (330330630636).

Almost surely, 2^{1211212312321} is an apocalyptic number.

1211212312321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211212312321 is a deficient number, since it is larger than the sum of its proper divisors (110110210223).

1211212312321 is a wasteful number, since it uses less digits than its factorization.

1211212312321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110110210222.

The product of its digits is 288, while the sum is 22.

Adding to 1211212312321 its reverse (1232132121121), we get a palindrome (2443344433442).

The spelling of 1211212312321 in words is "one trillion, two hundred eleven billion, two hundred twelve million, three hundred twelve thousand, three hundred twenty-one".