20558898121 has 2 divisors, whose sum is σ = 20558898122. Its totient is φ = 20558898120.

The previous prime is 20558898103. The next prime is 20558898131. The reversal of 20558898121 is 12189885502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18212852025 + 2346046096 = 134955^2 + 48436^2 .

It is a cyclic number.

It is not a de Polignac number, because 20558898121 - 2⁹ = 20558897609 is a prime.

It is not a weakly prime, because it can be changed into another prime (20558898131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10279449060 + 10279449061.

It is an arithmetic number, because the mean of its divisors is an integer number (10279449061).

Almost surely, 2^20558898121 is an apocalyptic number.

It is an amenable number.

20558898121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20558898121 is an equidigital number, since it uses as much as digits as its factorization.

20558898121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 460800, while the sum is 49.

The spelling of 20558898121 in words is "twenty billion, five hundred fifty-eight million, eight hundred ninety-eight thousand, one hundred twenty-one".