85081631 has 2 divisors, whose sum is σ = 85081632. Its totient is φ = 85081630.

The previous prime is 85081627. The next prime is 85081681. The reversal of 85081631 is 13618058.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85081631 - 2² = 85081627 is a prime.

It is a super-2 number, since 2×85081631² = 14477767867240322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85081681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42540815 + 42540816.

It is an arithmetic number, because the mean of its divisors is an integer number (42540816).

Almost surely, 2^85081631 is an apocalyptic number.

85081631 is a deficient number, since it is larger than the sum of its proper divisors (1).

85081631 is an equidigital number, since it uses as much as digits as its factorization.

85081631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 85081631 is about 9223.9704574549. The cubic root of 85081631 is about 439.8236741833.

Adding to 85081631 its reverse (13618058), we get a palindrome (98699689).

The spelling of 85081631 in words is "eighty-five million, eighty-one thousand, six hundred thirty-one".