1000021221191 has 2 divisors, whose sum is σ = 1000021221192. Its totient is φ = 1000021221190.

The previous prime is 1000021221179. The next prime is 1000021221193. The reversal of 1000021221191 is 1911221200001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1000021221191 - 2¹⁰ = 1000021220167 is a prime.

Together with 1000021221193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000021221193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500010610595 + 500010610596.

It is an arithmetic number, because the mean of its divisors is an integer number (500010610596).

Almost surely, 2^{1000021221191} is an apocalyptic number.

1000021221191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000021221191 is an equidigital number, since it uses as much as digits as its factorization.

1000021221191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 20.

Adding to 1000021221191 its reverse (1911221200001), we get a palindrome (2911242421192).

The spelling of 1000021221191 in words is "one trillion, twenty-one million, two hundred twenty-one thousand, one hundred ninety-one".