1121212221821 has 2 divisors, whose sum is σ = 1121212221822. Its totient is φ = 1121212221820.

The previous prime is 1121212221809. The next prime is 1121212221889. The reversal of 1121212221821 is 1281222121211.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1103613280900 + 17598940921 = 1050530^2 + 132661^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121212221821 - 2²² = 1121208027517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1121212223821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560606110910 + 560606110911.

It is an arithmetic number, because the mean of its divisors is an integer number (560606110911).

Almost surely, 2^{1121212221821} is an apocalyptic number.

It is an amenable number.

1121212221821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121212221821 is an equidigital number, since it uses as much as digits as its factorization.

1121212221821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 512, while the sum is 26.

The spelling of 1121212221821 in words is "one trillion, one hundred twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, eight hundred twenty-one".