2064443981 has 4 divisors (see below), whose sum is σ = 2064547932. Its totient is φ = 2064340032.

The previous prime is 2064443963. The next prime is 2064443987. The reversal of 2064443981 is 1893444602.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1775273956 + 289170025 = 42134^2 + 17005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2064443981 is a prime.

It is a super-2 number, since 2×2064443981² = 8523857901374256722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2064443987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11870 + ... + 65343.

It is an arithmetic number, because the mean of its divisors is an integer number (516136983).

Almost surely, 2^2064443981 is an apocalyptic number.

It is an amenable number.

2064443981 is a deficient number, since it is larger than the sum of its proper divisors (103951).

2064443981 is an equidigital number, since it uses as much as digits as its factorization.

2064443981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103950.

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 2064443981 is about 45436.1527970844. The cubic root of 2064443981 is about 1273.3106383679.

The spelling of 2064443981 in words is "two billion, sixty-four million, four hundred forty-three thousand, nine hundred eighty-one".