105717861521 has 2 divisors, whose sum is σ = 105717861522. Its totient is φ = 105717861520.

The previous prime is 105717861481. The next prime is 105717861533. The reversal of 105717861521 is 125168717501.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101975480896 + 3742380625 = 319336^2 + 61175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-105717861521 is a prime.

It is a super-2 number, since 2×105717861521² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (105717861581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52858930760 + 52858930761.

It is an arithmetic number, because the mean of its divisors is an integer number (52858930761).

Almost surely, 2^105717861521 is an apocalyptic number.

It is an amenable number.

105717861521 is a deficient number, since it is larger than the sum of its proper divisors (1).

105717861521 is an equidigital number, since it uses as much as digits as its factorization.

105717861521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 117600, while the sum is 44.

The spelling of 105717861521 in words is "one hundred five billion, seven hundred seventeen million, eight hundred sixty-one thousand, five hundred twenty-one".