21132020317 has 2 divisors, whose sum is σ = 21132020318. Its totient is φ = 21132020316.

The previous prime is 21132020311. The next prime is 21132020321. The reversal of 21132020317 is 71302023112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14946040516 + 6185979801 = 122254^2 + 78651^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21132020317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21132020311) 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 as a sum of consecutive naturals, namely, 10566010158 + 10566010159.

It is an arithmetic number, because the mean of its divisors is an integer number (10566010159).

Almost surely, 2^21132020317 is an apocalyptic number.

It is an amenable number.

21132020317 is a deficient number, since it is larger than the sum of its proper divisors (1).

21132020317 is an equidigital number, since it uses as much as digits as its factorization.

21132020317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 22.

Adding to 21132020317 its reverse (71302023112), we get a palindrome (92434043429).

The spelling of 21132020317 in words is "twenty-one billion, one hundred thirty-two million, twenty thousand, three hundred seventeen".