1001556864001 has 2 divisors, whose sum is σ = 1001556864002. Its totient is φ = 1001556864000.

The previous prime is 1001556863981. The next prime is 1001556864103. The reversal of 1001556864001 is 1004686551001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 994697049025 + 6859814976 = 997345^2 + 82824^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001556864001 - 2¹¹ = 1001556861953 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001556861001) by changing a digit.

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 as a sum of consecutive naturals, namely, 500778432000 + 500778432001.

It is an arithmetic number, because the mean of its divisors is an integer number (500778432001).

Almost surely, 2^{1001556864001} is an apocalyptic number.

It is an amenable number.

1001556864001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001556864001 is an equidigital number, since it uses as much as digits as its factorization.

1001556864001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 1001556864001 in words is "one trillion, one billion, five hundred fifty-six million, eight hundred sixty-four thousand, one".