1321212121211 has 4 divisors (see below), whose sum is σ = 1321437551424. Its totient is φ = 1320986691000.

The previous prime is 1321212121199. The next prime is 1321212121267. The reversal of 1321212121211 is 1121212121231.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321212121211 is a prime.

It is a super-2 number, since 2×1321212121211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321212127211) 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, 112706315 + ... + 112718036.

It is an arithmetic number, because the mean of its divisors is an integer number (330359387856).

Almost surely, 2^{1321212121211} is an apocalyptic number.

1321212121211 is a deficient number, since it is larger than the sum of its proper divisors (225430213).

1321212121211 is an equidigital number, since it uses as much as digits as its factorization.

1321212121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225430212.

The product of its digits is 96, while the sum is 20.

Adding to 1321212121211 its sum of digits (20), we get a palindrome (1321212121231).

Adding to 1321212121211 its reverse (1121212121231), we get a palindrome (2442424242442).

The spelling of 1321212121211 in words is "one trillion, three hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred eleven".