21220120331 has 2 divisors, whose sum is σ = 21220120332. Its totient is φ = 21220120330.

The previous prime is 21220120253. The next prime is 21220120343. The reversal of 21220120331 is 13302102212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220120331 is a prime.

It is a super-2 number, since 2×21220120331² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21220126331) 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, 10610060165 + 10610060166.

It is an arithmetic number, because the mean of its divisors is an integer number (10610060166).

Almost surely, 2^21220120331 is an apocalyptic number.

21220120331 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220120331 is an equidigital number, since it uses as much as digits as its factorization.

21220120331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21220120331 its reverse (13302102212), we get a palindrome (34522222543).

The spelling of 21220120331 in words is "twenty-one billion, two hundred twenty million, one hundred twenty thousand, three hundred thirty-one".