20000439644 has 6 divisors (see below), whose sum is σ = 35000769384. Its totient is φ = 10000219820.

The previous prime is 20000439631. The next prime is 20000439647. The reversal of 20000439644 is 44693400002.

It is a self number, because there is not a number n which added to its sum of digits gives 20000439644.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000439647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2500054952 + ... + 2500054959.

It is an arithmetic number, because the mean of its divisors is an integer number (5833461564).

Almost surely, 2^20000439644 is an apocalyptic number.

It is an amenable number.

20000439644 is a deficient number, since it is larger than the sum of its proper divisors (15000329740).

20000439644 is a wasteful number, since it uses less digits than its factorization.

20000439644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5000109915 (or 5000109913 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

Adding to 20000439644 its reverse (44693400002), we get a palindrome (64693839646).

The spelling of 20000439644 in words is "twenty billion, four hundred thirty-nine thousand, six hundred forty-four".