20402372281 has 2 divisors, whose sum is σ = 20402372282. Its totient is φ = 20402372280.

The previous prime is 20402372261. The next prime is 20402372293. The reversal of 20402372281 is 18227320402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20367856656 + 34515625 = 142716^2 + 5875^2 .

It is a cyclic number.

It is not a de Polignac number, because 20402372281 - 2¹³ = 20402364089 is a prime.

It is a super-2 number, since 2×20402372281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20402372251) 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, 10201186140 + 10201186141.

It is an arithmetic number, because the mean of its divisors is an integer number (10201186141).

Almost surely, 2^20402372281 is an apocalyptic number.

It is an amenable number.

20402372281 is a deficient number, since it is larger than the sum of its proper divisors (1).

20402372281 is an equidigital number, since it uses as much as digits as its factorization.

20402372281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10752, while the sum is 31.

Adding to 20402372281 its reverse (18227320402), we get a palindrome (38629692683).

The spelling of 20402372281 in words is "twenty billion, four hundred two million, three hundred seventy-two thousand, two hundred eighty-one".