215421207126109 has 2 divisors, whose sum is σ = 215421207126110. Its totient is φ = 215421207126108.

The previous prime is 215421207126077. The next prime is 215421207126121. The reversal of 215421207126109 is 901621702124512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207414089926884 + 8007117199225 = 14401878^2 + 2829685^2 .

It is a cyclic number.

It is not a de Polignac number, because 215421207126109 - 2⁵ = 215421207126077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215421207126179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107710603563054 + 107710603563055.

It is an arithmetic number, because the mean of its divisors is an integer number (107710603563055).

Almost surely, 2^{215421207126109} is an apocalyptic number.

It is an amenable number.

215421207126109 is a deficient number, since it is larger than the sum of its proper divisors (1).

215421207126109 is an equidigital number, since it uses as much as digits as its factorization.

215421207126109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 215421207126109 in words is "two hundred fifteen trillion, four hundred twenty-one billion, two hundred seven million, one hundred twenty-six thousand, one hundred nine".