4464639981 has 12 divisors (see below), whose sum is σ = 6495998652. Its totient is φ = 2954700096.

The previous prime is 4464639973. The next prime is 4464640001. The reversal of 4464639981 is 1899364644.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1945603881 + 2519036100 = 44109^2 + 50190^2 .

It is not a de Polignac number, because 4464639981 - 2³ = 4464639973 is a prime.

It is a super-2 number, since 2×4464639981² = 39866020319887360722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4464639481) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1809246 + ... + 1811711.

It is an arithmetic number, because the mean of its divisors is an integer number (541333221).

Almost surely, 2^4464639981 is an apocalyptic number.

It is an amenable number.

4464639981 is a deficient number, since it is larger than the sum of its proper divisors (2031358671).

4464639981 is a wasteful number, since it uses less digits than its factorization.

4464639981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3621100 (or 3621097 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 54.

The square root of 4464639981 is about 66817.9615148502. The cubic root of 4464639981 is about 1646.6279441786.

The spelling of 4464639981 in words is "four billion, four hundred sixty-four million, six hundred thirty-nine thousand, nine hundred eighty-one".