1989885864961 has 16 divisors (see below), whose sum is σ = 2046728822400. Its totient is φ = 1933205902848.

The previous prime is 1989885864937. The next prime is 1989885864971. The reversal of 1989885864961 is 1694685889891.

It is a cyclic number.

It is not a de Polignac number, because 1989885864961 - 2¹⁹ = 1989885340673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989885864971) 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 in 15 ways as a sum of consecutive naturals, for example, 91524430 + ... + 91546168.

It is an arithmetic number, because the mean of its divisors is an integer number (127920551400).

Almost surely, 2^{1989885864961} is an apocalyptic number.

It is an amenable number.

1989885864961 is a deficient number, since it is larger than the sum of its proper divisors (56842957439).

1989885864961 is a wasteful number, since it uses less digits than its factorization.

1989885864961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25368.

The product of its digits is 2149908480, while the sum is 82.

The spelling of 1989885864961 in words is "one trillion, nine hundred eighty-nine billion, eight hundred eighty-five million, eight hundred sixty-four thousand, nine hundred sixty-one".