1001156116561 has 16 divisors (see below), whose sum is σ = 1081624181760. Its totient is φ = 923822320960.

The previous prime is 1001156116517. The next prime is 1001156116633. The reversal of 1001156116561 is 1656116511001.

It is a cyclic number.

It is not a de Polignac number, because 1001156116561 - 2⁹ = 1001156116049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1001156116061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152256 + ... + 1423198.

It is an arithmetic number, because the mean of its divisors is an integer number (67601511360).

Almost surely, 2^{1001156116561} is an apocalyptic number.

It is an amenable number.

1001156116561 is a deficient number, since it is larger than the sum of its proper divisors (80468065199).

1001156116561 is a wasteful number, since it uses less digits than its factorization.

1001156116561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272176.

The product of its (nonzero) digits is 5400, while the sum is 34.

The spelling of 1001156116561 in words is "one trillion, one billion, one hundred fifty-six million, one hundred sixteen thousand, five hundred sixty-one".