2001765681 has 24 divisors (see below), whose sum is σ = 2916950400. Its totient is φ = 1322775456.

The previous prime is 2001765679. The next prime is 2001765683. The reversal of 2001765681 is 1865671002.

2001765681 is a `hidden beast` number, since 20 + 0 + 1 + 76 + 568 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (2001765679) and next prime (2001765683).

It is not a de Polignac number, because 2001765681 - 2¹ = 2001765679 is a prime.

It is a super-2 number, since 2×2001765681² = 8014131683258787522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2001765683) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 785896 + ... + 788438.

It is an arithmetic number, because the mean of its divisors is an integer number (121539600).

Almost surely, 2^2001765681 is an apocalyptic number.

It is an amenable number.

2001765681 is a deficient number, since it is larger than the sum of its proper divisors (915184719).

2001765681 is a wasteful number, since it uses less digits than its factorization.

2001765681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3285 (or 3282 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 2001765681 is about 44741.0961086114. The cubic root of 2001765681 is about 1260.2917106147.

The spelling of 2001765681 in words is "two billion, one million, seven hundred sixty-five thousand, six hundred eighty-one".