1001081661 has 8 divisors (see below), whose sum is σ = 1335352704. Its totient is φ = 667099200.

The previous prime is 1001081659. The next prime is 1001081677. The reversal of 1001081661 is 1661801001.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1001081661 - 2¹ = 1001081659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001081651) 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 7 ways as a sum of consecutive naturals, for example, 63916 + ... + 78021.

It is an arithmetic number, because the mean of its divisors is an integer number (166919088).

Almost surely, 2^1001081661 is an apocalyptic number.

It is an amenable number.

1001081661 is a deficient number, since it is larger than the sum of its proper divisors (334271043).

1001081661 is a wasteful number, since it uses less digits than its factorization.

1001081661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144291.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 1001081661 is about 31639.8745414706. The cubic root of 1001081661 is about 1000.3604237458.

Adding to 1001081661 its reverse (1661801001), we get a palindrome (2662882662).

The spelling of 1001081661 in words is "one billion, one million, eighty-one thousand, six hundred sixty-one".