87111985693 has 2 divisors, whose sum is σ = 87111985694. Its totient is φ = 87111985692.

The previous prime is 87111985627. The next prime is 87111985699. The reversal of 87111985693 is 39658911178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63800192569 + 23311793124 = 252587^2 + 152682^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87111985693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87111985699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43555992846 + 43555992847.

It is an arithmetic number, because the mean of its divisors is an integer number (43555992847).

Almost surely, 2^87111985693 is an apocalyptic number.

It is an amenable number.

87111985693 is a deficient number, since it is larger than the sum of its proper divisors (1).

87111985693 is an equidigital number, since it uses as much as digits as its factorization.

87111985693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3265920, while the sum is 58.

The spelling of 87111985693 in words is "eighty-seven billion, one hundred eleven million, nine hundred eighty-five thousand, six hundred ninety-three".