2001221001187 has 2 divisors, whose sum is σ = 2001221001188. Its totient is φ = 2001221001186.

The previous prime is 2001221001179. The next prime is 2001221001193. The reversal of 2001221001187 is 7811001221002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2001221001187 - 2³ = 2001221001179 is a prime.

It is not a weakly prime, because it can be changed into another prime (2001221001127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000610500593 + 1000610500594.

It is an arithmetic number, because the mean of its divisors is an integer number (1000610500594).

Almost surely, 2^{2001221001187} is an apocalyptic number.

2001221001187 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001221001187 is an equidigital number, since it uses as much as digits as its factorization.

2001221001187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 25.

Adding to 2001221001187 its reverse (7811001221002), we get a palindrome (9812222222189).

The spelling of 2001221001187 in words is "two trillion, one billion, two hundred twenty-one million, one thousand, one hundred eighty-seven".