20920204447321 has 3 divisors (see below), whose sum is σ = 20920209021183. Its totient is φ = 20920199873460.

The previous prime is 20920204447283. The next prime is 20920204447339. The reversal of 20920204447321 is 12374440202902.

The square root of 20920204447321 is 4573861.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 13513424475721 + 7406779971600 = 3676061^2 + 2721540^2 .

It is not a de Polignac number, because 20920204447321 - 2¹⁹ = 20920203923033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20920204447721) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2286931 + ... + 6860791.

It is an arithmetic number, because the mean of its divisors is an integer number (6973403007061).

Almost surely, 2^{20920204447321} is an apocalyptic number.

20920204447321 is the 4573861-st square number.

20920204447321 is the 2286931-st centered octagonal number.

It is an amenable number.

20920204447321 is a deficient number, since it is larger than the sum of its proper divisors (4573862).

20920204447321 is an frugal number, since it uses more digits than its factorization.

20920204447321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9147722 (or 4573861 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 40.

The spelling of 20920204447321 in words is "twenty trillion, nine hundred twenty billion, two hundred four million, four hundred forty-seven thousand, three hundred twenty-one".