10781171521 has 2 divisors, whose sum is σ = 10781171522. Its totient is φ = 10781171520.

The previous prime is 10781171519. The next prime is 10781171549. The reversal of 10781171521 is 12517118701.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10711215025 + 69956496 = 103495^2 + 8364^2 .

It is a cyclic number.

It is not a de Polignac number, because 10781171521 - 2¹ = 10781171519 is a prime.

Together with 10781171519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (10781171561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5390585760 + 5390585761.

It is an arithmetic number, because the mean of its divisors is an integer number (5390585761).

Almost surely, 2^10781171521 is an apocalyptic number.

It is an amenable number.

10781171521 is a deficient number, since it is larger than the sum of its proper divisors (1).

10781171521 is an equidigital number, since it uses as much as digits as its factorization.

10781171521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 34.

The spelling of 10781171521 in words is "ten billion, seven hundred eighty-one million, one hundred seventy-one thousand, five hundred twenty-one".