85815481 has 2 divisors, whose sum is σ = 85815482. Its totient is φ = 85815480.

The previous prime is 85815463. The next prime is 85815497. The reversal of 85815481 is 18451858.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51194025 + 34621456 = 7155^2 + 5884^2 .

It is a cyclic number.

It is not a de Polignac number, because 85815481 - 2⁵ = 85815449 is a prime.

It is a super-2 number, since 2×85815481² = 14728593558522722, which contains 22 as substring.

It is equal to p_4988371 and since 85815481 and 4988371 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (85815421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42907740 + 42907741.

It is an arithmetic number, because the mean of its divisors is an integer number (42907741).

Almost surely, 2^85815481 is an apocalyptic number.

It is an amenable number.

85815481 is a deficient number, since it is larger than the sum of its proper divisors (1).

85815481 is an equidigital number, since it uses as much as digits as its factorization.

85815481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51200, while the sum is 40.

The square root of 85815481 is about 9263.6645556713. The cubic root of 85815481 is about 441.0845850131.

The spelling of 85815481 in words is "eighty-five million, eight hundred fifteen thousand, four hundred eighty-one".