1001666601 has 16 divisors (see below), whose sum is σ = 1598101120. Its totient is φ = 616410000.

The previous prime is 1001666597. The next prime is 1001666621. The reversal of 1001666601 is 1066661001.

1001666601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1001666601 - 2² = 1001666597 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1001666621) 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, 1426525 + ... + 1427226.

It is an arithmetic number, because the mean of its divisors is an integer number (99881320).

Almost surely, 2^1001666601 is an apocalyptic number.

It is an amenable number.

1001666601 is a deficient number, since it is larger than the sum of its proper divisors (596434519).

1001666601 is a wasteful number, since it uses less digits than its factorization.

1001666601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2853773 (or 2853767 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1001666601 is about 31649.1169071113. The cubic root of 1001666601 is about 1000.5552253344. Note that the first 3 decimals are identical.

The spelling of 1001666601 in words is "one billion, one million, six hundred sixty-six thousand, six hundred one".