20357220644 has 6 divisors (see below), whose sum is σ = 35625136134. Its totient is φ = 10178610320.

The previous prime is 20357220643. The next prime is 20357220727. The reversal of 20357220644 is 44602275302.

It can be written as a sum of positive squares in only one way, i.e., 20188999744 + 168220900 = 142088^2 + 12970^2 .

It is not an unprimeable number, because it can be changed into a prime (20357220643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2544652577 + ... + 2544652584.

It is an arithmetic number, because the mean of its divisors is an integer number (5937522689).

Almost surely, 2^20357220644 is an apocalyptic number.

It is an amenable number.

20357220644 is a deficient number, since it is larger than the sum of its proper divisors (15267915490).

20357220644 is a wasteful number, since it uses less digits than its factorization.

20357220644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5089305165 (or 5089305163 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 35.

Adding to 20357220644 its reverse (44602275302), we get a palindrome (64959495946).

The spelling of 20357220644 in words is "twenty billion, three hundred fifty-seven million, two hundred twenty thousand, six hundred forty-four".