20555220137 has 2 divisors, whose sum is σ = 20555220138. Its totient is φ = 20555220136.

The previous prime is 20555220113. The next prime is 20555220227. The reversal of 20555220137 is 73102255502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19574528281 + 980691856 = 139909^2 + 31316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20555220137 is a prime.

It is not a weakly prime, because it can be changed into another prime (20555225137) 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, 10277610068 + 10277610069.

It is an arithmetic number, because the mean of its divisors is an integer number (10277610069).

Almost surely, 2^20555220137 is an apocalyptic number.

It is an amenable number.

20555220137 is a deficient number, since it is larger than the sum of its proper divisors (1).

20555220137 is an equidigital number, since it uses as much as digits as its factorization.

20555220137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21000, while the sum is 32.

Adding to 20555220137 its reverse (73102255502), we get a palindrome (93657475639).

The spelling of 20555220137 in words is "twenty billion, five hundred fifty-five million, two hundred twenty thousand, one hundred thirty-seven".