1220865987805 has 16 divisors (see below), whose sum is σ = 1487859834240. Its totient is φ = 961497738432.

The previous prime is 1220865987703. The next prime is 1220865987853. The reversal of 1220865987805 is 5087895680221.

It is a cyclic number.

It is not a de Polignac number, because 1220865987805 - 2¹⁷ = 1220865856733 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 646554 + ... + 1691083.

It is an arithmetic number, because the mean of its divisors is an integer number (92991239640).

Almost surely, 2^{1220865987805} is an apocalyptic number.

It is an amenable number.

1220865987805 is a deficient number, since it is larger than the sum of its proper divisors (266993846435).

1220865987805 is a wasteful number, since it uses less digits than its factorization.

1220865987805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2339268.

The product of its (nonzero) digits is 19353600, while the sum is 61.

The spelling of 1220865987805 in words is "one trillion, two hundred twenty billion, eight hundred sixty-five million, nine hundred eighty-seven thousand, eight hundred five".