2001644761 has 8 divisors (see below), whose sum is σ = 2037730464. Its totient is φ = 1965874560.

The previous prime is 2001644731. The next prime is 2001644809. The reversal of 2001644761 is 1674461002.

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

It is a cyclic number.

It is not a de Polignac number, because 2001644761 - 2⁷ = 2001644633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001644731) 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, 66055 + ... + 91468.

It is an arithmetic number, because the mean of its divisors is an integer number (254716308).

Almost surely, 2^2001644761 is an apocalyptic number.

It is an amenable number.

2001644761 is a deficient number, since it is larger than the sum of its proper divisors (36085703).

2001644761 is a wasteful number, since it uses less digits than its factorization.

2001644761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157751.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 2001644761 is about 44739.7447578772. The cubic root of 2001644761 is about 1260.2663334283.

The spelling of 2001644761 in words is "two billion, one million, six hundred forty-four thousand, seven hundred sixty-one".