81231086 has 16 divisors (see below), whose sum is σ = 127180368. Its totient is φ = 38875200.

The previous prime is 81231071. The next prime is 81231089. The reversal of 81231086 is 68013218.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81231089) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5000 + ... + 13691.

It is an arithmetic number, because the mean of its divisors is an integer number (7948773).

Almost surely, 2^81231086 is an apocalyptic number.

81231086 is a deficient number, since it is larger than the sum of its proper divisors (45949282).

81231086 is a wasteful number, since it uses less digits than its factorization.

81231086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18787.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 81231086 is about 9012.8289676438. The cubic root of 81231086 is about 433.0859417619.

The spelling of 81231086 in words is "eighty-one million, two hundred thirty-one thousand, eighty-six".