215707755121 has 2 divisors, whose sum is σ = 215707755122. Its totient is φ = 215707755120.

The previous prime is 215707755083. The next prime is 215707755157. The reversal of 215707755121 is 121557707512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115573481521 + 100134273600 = 339961^2 + 316440^2 .

It is a cyclic number.

It is not a de Polignac number, because 215707755121 - 2⁷ = 215707754993 is a prime.

It is not a weakly prime, because it can be changed into another prime (215707705121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107853877560 + 107853877561.

It is an arithmetic number, because the mean of its divisors is an integer number (107853877561).

Almost surely, 2^215707755121 is an apocalyptic number.

It is an amenable number.

215707755121 is a deficient number, since it is larger than the sum of its proper divisors (1).

215707755121 is an equidigital number, since it uses as much as digits as its factorization.

215707755121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 171500, while the sum is 43.

The spelling of 215707755121 in words is "two hundred fifteen billion, seven hundred seven million, seven hundred fifty-five thousand, one hundred twenty-one".