20660442644 has 6 divisors (see below), whose sum is σ = 36155774634. Its totient is φ = 10330221320.

The previous prime is 20660442637. The next prime is 20660442659. The reversal of 20660442644 is 44624406602.

It can be written as a sum of positive squares in only one way, i.e., 20635322500 + 25120144 = 143650^2 + 5012^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20660442598 and 20660442607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2582555327 + ... + 2582555334.

It is an arithmetic number, because the mean of its divisors is an integer number (6025962439).

Almost surely, 2^20660442644 is an apocalyptic number.

It is an amenable number.

20660442644 is a deficient number, since it is larger than the sum of its proper divisors (15495331990).

20660442644 is a wasteful number, since it uses less digits than its factorization.

20660442644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5165110665 (or 5165110663 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 38.

The spelling of 20660442644 in words is "twenty billion, six hundred sixty million, four hundred forty-two thousand, six hundred forty-four".