20815752722 has 6 divisors (see below), whose sum is σ = 31223935143. Its totient is φ = 10407774342.

The previous prime is 20815752709. The next prime is 20815752743. The reversal of 20815752722 is 22725751802.

It can be written as a sum of positive squares in only one way, i.e., 10407876361 + 10407876361 = 102019^2 + 102019^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=102019.

It is a super-2 number, since 2×20815752722² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20815752722.

It is an unprimeable number.

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 2 ways as a sum of consecutive naturals, for example, 153029 + ... + 255047.

Almost surely, 2^20815752722 is an apocalyptic number.

20815752722 is a deficient number, since it is larger than the sum of its proper divisors (10408182421).

20815752722 is an frugal number, since it uses more digits than its factorization.

20815752722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204040 (or 102021 counting only the distinct ones).

The product of its (nonzero) digits is 156800, while the sum is 41.

The spelling of 20815752722 in words is "twenty billion, eight hundred fifteen million, seven hundred fifty-two thousand, seven hundred twenty-two".