81075831 has 16 divisors (see below), whose sum is σ = 114925440. Its totient is φ = 50695200.

The previous prime is 81075809. The next prime is 81075833. The reversal of 81075831 is 13857018.

It is not a de Polignac number, because 81075831 - 2¹³ = 81067639 is a prime.

It is a super-2 number, since 2×81075831² = 13146580744681122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81075792 and 81075801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81075833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1285 + ... + 12798.

It is an arithmetic number, because the mean of its divisors is an integer number (7182840).

Almost surely, 2^81075831 is an apocalyptic number.

81075831 is a deficient number, since it is larger than the sum of its proper divisors (33849609).

81075831 is a wasteful number, since it uses less digits than its factorization.

81075831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14206.

The product of its (nonzero) digits is 6720, while the sum is 33.

The square root of 81075831 is about 9004.2118477966. The cubic root of 81075831 is about 432.8098502473.

The spelling of 81075831 in words is "eighty-one million, seventy-five thousand, eight hundred thirty-one".