20321331066397 has 4 divisors (see below), whose sum is σ = 20321688120160. Its totient is φ = 20320974012636.

The previous prime is 20321331066349. The next prime is 20321331066433. The reversal of 20321331066397 is 79366013312302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20321331066397 is a prime.

It is a super-2 number, since 2×20321331066397² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321331066307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178441497 + ... + 178555342.

It is an arithmetic number, because the mean of its divisors is an integer number (5080422030040).

Almost surely, 2^{20321331066397} is an apocalyptic number.

It is an amenable number.

20321331066397 is a deficient number, since it is larger than the sum of its proper divisors (357053763).

20321331066397 is an equidigital number, since it uses as much as digits as its factorization.

20321331066397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357053762.

The product of its (nonzero) digits is 734832, while the sum is 46.

Adding to 20321331066397 its reverse (79366013312302), we get a palindrome (99687344378699).

The spelling of 20321331066397 in words is "twenty trillion, three hundred twenty-one billion, three hundred thirty-one million, sixty-six thousand, three hundred ninety-seven".