2001831649321 has 27 divisors (see below), whose sum is σ = 2351872926039. Its totient is φ = 1698919813248.

The previous prime is 2001831649309. The next prime is 2001831649357. The reversal of 2001831649321 is 1239461381002.

It is a happy number.

The square root of 2001831649321 is 1414861.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 964204199721 + 1037627449600 = 981939^2 + 1018640^2 .

It is not a de Polignac number, because 2001831649321 - 2¹⁵ = 2001831616553 is a prime.

It is a super-2 number, since 2×2001831649321² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2001831649621) 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 26 ways as a sum of consecutive naturals, for example, 1059729945 + ... + 1059731833.

Almost surely, 2^{2001831649321} is an apocalyptic number.

2001831649321 is the 1414861-st square number.

2001831649321 is the 707431-st centered octagonal number.

It is an amenable number.

2001831649321 is a deficient number, since it is larger than the sum of its proper divisors (350041276718).

2001831649321 is an frugal number, since it uses more digits than its factorization.

2001831649321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4006 (or 2003 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The spelling of 2001831649321 in words is "two trillion, one billion, eight hundred thirty-one million, six hundred forty-nine thousand, three hundred twenty-one".