2001121751 has 2 divisors, whose sum is σ = 2001121752. Its totient is φ = 2001121750.

The previous prime is 2001121747. The next prime is 2001121753. The reversal of 2001121751 is 1571211002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2001121751 - 2² = 2001121747 is a prime.

It is a Sophie Germain prime.

Together with 2001121753, 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 (2001121753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000560875 + 1000560876.

It is an arithmetic number, because the mean of its divisors is an integer number (1000560876).

Almost surely, 2^2001121751 is an apocalyptic number.

2001121751 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001121751 is an equidigital number, since it uses as much as digits as its factorization.

2001121751 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 140, while the sum is 20.

The square root of 2001121751 is about 44733.8993493749. The cubic root of 2001121751 is about 1260.1565588196.

Adding to 2001121751 its reverse (1571211002), we get a palindrome (3572332753).

The spelling of 2001121751 in words is "two billion, one million, one hundred twenty-one thousand, seven hundred fifty-one".