20321012564 has 12 divisors (see below), whose sum is σ = 35564410644. Its totient is φ = 10159752384.

The previous prime is 20321012561. The next prime is 20321012603. The reversal of 20321012564 is 46521012302.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4918216900 + 15402795664 = 70130^2 + 124108^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321012561) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 125489 + ... + 237464.

It is an arithmetic number, because the mean of its divisors is an integer number (2963700887).

Almost surely, 2^20321012564 is an apocalyptic number.

It is an amenable number.

20321012564 is a deficient number, since it is larger than the sum of its proper divisors (15243398080).

20321012564 is a wasteful number, since it uses less digits than its factorization.

20321012564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376954 (or 376952 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 20321012564 its reverse (46521012302), we get a palindrome (66842024866).

The spelling of 20321012564 in words is "twenty billion, three hundred twenty-one million, twelve thousand, five hundred sixty-four".