85057555981 has 2 divisors, whose sum is σ = 85057555982. Its totient is φ = 85057555980.

The previous prime is 85057555967. The next prime is 85057555993. The reversal of 85057555981 is 18955575058.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85056806025 + 749956 = 291645^2 + 866^2 .

It is a cyclic number.

It is not a de Polignac number, because 85057555981 - 2¹³ = 85057547789 is a prime.

It is a super-2 number, since 2×85057555981² (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 (85057555381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42528777990 + 42528777991.

It is an arithmetic number, because the mean of its divisors is an integer number (42528777991).

Almost surely, 2^85057555981 is an apocalyptic number.

It is an amenable number.

85057555981 is a deficient number, since it is larger than the sum of its proper divisors (1).

85057555981 is an equidigital number, since it uses as much as digits as its factorization.

85057555981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12600000, while the sum is 58.

The spelling of 85057555981 in words is "eighty-five billion, fifty-seven million, five hundred fifty-five thousand, nine hundred eighty-one".