878117035134421 has 2 divisors, whose sum is σ = 878117035134422. Its totient is φ = 878117035134420.

The previous prime is 878117035134419. The next prime is 878117035134481. The reversal of 878117035134421 is 124431530711878.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 747318676636900 + 130798358497521 = 27337130^2 + 11436711^2 .

It is a cyclic number.

It is not a de Polignac number, because 878117035134421 - 2¹ = 878117035134419 is a prime.

Together with 878117035134419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (878117035134481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 439058517567210 + 439058517567211.

It is an arithmetic number, because the mean of its divisors is an integer number (439058517567211).

Almost surely, 2^{878117035134421} is an apocalyptic number.

It is an amenable number.

878117035134421 is a deficient number, since it is larger than the sum of its proper divisors (1).

878117035134421 is an equidigital number, since it uses as much as digits as its factorization.

878117035134421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 878117035134421 in words is "eight hundred seventy-eight trillion, one hundred seventeen billion, thirty-five million, one hundred thirty-four thousand, four hundred twenty-one".