2001082861 has 4 divisors (see below), whose sum is σ = 2009898432. Its totient is φ = 1992267292.

The previous prime is 2001082847. The next prime is 2001082901. The reversal of 2001082861 is 1682801002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1682801002 = 2 ⋅841400501.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001082861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001082841) 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, 4407445 + ... + 4407898.

It is an arithmetic number, because the mean of its divisors is an integer number (502474608).

Almost surely, 2^2001082861 is an apocalyptic number.

It is an amenable number.

2001082861 is a deficient number, since it is larger than the sum of its proper divisors (8815571).

2001082861 is an equidigital number, since it uses as much as digits as its factorization.

2001082861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8815570.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 2001082861 is about 44733.4646657287. The cubic root of 2001082861 is about 1260.1483954305.

Adding to 2001082861 its reverse (1682801002), we get a palindrome (3683883863).

The spelling of 2001082861 in words is "two billion, one million, eighty-two thousand, eight hundred sixty-one".