2001166553 has 2 divisors, whose sum is σ = 2001166554. Its totient is φ = 2001166552.

The previous prime is 2001166523. The next prime is 2001166561. The reversal of 2001166553 is 3556611002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1025728729 + 975437824 = 32027^2 + 31232^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001166553 - 2¹⁶ = 2001101017 is a prime.

It is not a weakly prime, because it can be changed into another prime (2001166523) 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, 1000583276 + 1000583277.

It is an arithmetic number, because the mean of its divisors is an integer number (1000583277).

Almost surely, 2^2001166553 is an apocalyptic number.

It is an amenable number.

2001166553 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001166553 is an equidigital number, since it uses as much as digits as its factorization.

2001166553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 2001166553 is about 44734.4001077471. The cubic root of 2001166553 is about 1260.1659630638.

Adding to 2001166553 its reverse (3556611002), we get a palindrome (5557777555).

The spelling of 2001166553 in words is "two billion, one million, one hundred sixty-six thousand, five hundred fifty-three".