1001221187 has 2 divisors, whose sum is σ = 1001221188. Its totient is φ = 1001221186.

The previous prime is 1001221183. The next prime is 1001221223. The reversal of 1001221187 is 7811221001.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1001221187 - 2² = 1001221183 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001221183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500610593 + 500610594.

It is an arithmetic number, because the mean of its divisors is an integer number (500610594).

Almost surely, 2^1001221187 is an apocalyptic number.

1001221187 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001221187 is an equidigital number, since it uses as much as digits as its factorization.

1001221187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 224, while the sum is 23.

The square root of 1001221187 is about 31642.0793722537. The cubic root of 1001221187 is about 1000.4068967459.

Adding to 1001221187 its reverse (7811221001), we get a palindrome (8812442188).

The spelling of 1001221187 in words is "one billion, one million, two hundred twenty-one thousand, one hundred eighty-seven".