9919432135121 has 2 divisors, whose sum is σ = 9919432135122. Its totient is φ = 9919432135120.

The previous prime is 9919432135111. The next prime is 9919432135139. The reversal of 9919432135121 is 1215312349199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8493354320896 + 1426077814225 = 2914336^2 + 1194185^2 .

It is a cyclic number.

It is not a de Polignac number, because 9919432135121 - 2³⁴ = 9902252265937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9919432135121.

It is not a weakly prime, because it can be changed into another prime (9919432135111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4959716067560 + 4959716067561.

It is an arithmetic number, because the mean of its divisors is an integer number (4959716067561).

Almost surely, 2^{9919432135121} is an apocalyptic number.

It is an amenable number.

9919432135121 is a deficient number, since it is larger than the sum of its proper divisors (1).

9919432135121 is an equidigital number, since it uses as much as digits as its factorization.

9919432135121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 524880, while the sum is 50.

The spelling of 9919432135121 in words is "nine trillion, nine hundred nineteen billion, four hundred thirty-two million, one hundred thirty-five thousand, one hundred twenty-one".