1001071661 has 4 divisors (see below), whose sum is σ = 1003645500. Its totient is φ = 998497824.

The previous prime is 1001071613. The next prime is 1001071693. The reversal of 1001071661 is 1661701001.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 303108100 + 697963561 = 17410^2 + 26419^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001071661 - 2¹⁴ = 1001055277 is a prime.

It is a super-3 number, since 3×1001071661³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001071861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1286336 + ... + 1287113.

It is an arithmetic number, because the mean of its divisors is an integer number (250911375).

Almost surely, 2^1001071661 is an apocalyptic number.

It is an amenable number.

1001071661 is a deficient number, since it is larger than the sum of its proper divisors (2573839).

1001071661 is an equidigital number, since it uses as much as digits as its factorization.

1001071661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2573838.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 1001071661 is about 31639.7165126365. The cubic root of 1001071661 is about 1000.3570928029.

Adding to 1001071661 its reverse (1661701001), we get a palindrome (2662772662).

The spelling of 1001071661 in words is "one billion, one million, seventy-one thousand, six hundred sixty-one".