2001002101961 has 2 divisors, whose sum is σ = 2001002101962. Its totient is φ = 2001002101960.

The previous prime is 2001002101937. The next prime is 2001002102003. The reversal of 2001002101961 is 1691012001002.

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., 1998389358736 + 2612743225 = 1413644^2 + 51115^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001002101961 is a prime.

It is not a weakly prime, because it can be changed into another prime (2001002101061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000501050980 + 1000501050981.

It is an arithmetic number, because the mean of its divisors is an integer number (1000501050981).

Almost surely, 2^{2001002101961} is an apocalyptic number.

It is an amenable number.

2001002101961 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001002101961 is an equidigital number, since it uses as much as digits as its factorization.

2001002101961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 23.

Adding to 2001002101961 its reverse (1691012001002), we get a palindrome (3692014102963).

The spelling of 2001002101961 in words is "two trillion, one billion, two million, one hundred one thousand, nine hundred sixty-one".