85993539781 has 2 divisors, whose sum is σ = 85993539782. Its totient is φ = 85993539780.

The previous prime is 85993539641. The next prime is 85993539847. The reversal of 85993539781 is 18793539958.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80482853025 + 5510686756 = 283695^2 + 74234^2 .

It is a cyclic number.

It is not a de Polignac number, because 85993539781 - 2²¹ = 85991442629 is a prime.

It is a super-2 number, since 2×85993539781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85993539481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42996769890 + 42996769891.

It is an arithmetic number, because the mean of its divisors is an integer number (42996769891).

Almost surely, 2^85993539781 is an apocalyptic number.

It is an amenable number.

85993539781 is a deficient number, since it is larger than the sum of its proper divisors (1).

85993539781 is an equidigital number, since it uses as much as digits as its factorization.

85993539781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 73483200, while the sum is 67.

The spelling of 85993539781 in words is "eighty-five billion, nine hundred ninety-three million, five hundred thirty-nine thousand, seven hundred eighty-one".