115555660205521 has 2 divisors, whose sum is σ = 115555660205522. Its totient is φ = 115555660205520.

The previous prime is 115555660205477. The next prime is 115555660205539. The reversal of 115555660205521 is 125502066555511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78437237990400 + 37118422215121 = 8856480^2 + 6092489^2 .

It is a cyclic number.

It is not a de Polignac number, because 115555660205521 - 2⁹ = 115555660205009 is a prime.

It is a super-2 number, since 2×115555660205521² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (115555660205221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57777830102760 + 57777830102761.

It is an arithmetic number, because the mean of its divisors is an integer number (57777830102761).

Almost surely, 2^{115555660205521} is an apocalyptic number.

It is an amenable number.

115555660205521 is a deficient number, since it is larger than the sum of its proper divisors (1).

115555660205521 is an equidigital number, since it uses as much as digits as its factorization.

115555660205521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250000, while the sum is 49.

The spelling of 115555660205521 in words is "one hundred fifteen trillion, five hundred fifty-five billion, six hundred sixty million, two hundred five thousand, five hundred twenty-one".