81067731 has 16 divisors (see below), whose sum is σ = 112166400. Its totient is φ = 52018848.

The previous prime is 81067717. The next prime is 81067733. The reversal of 81067731 is 13776018.

It is not a de Polignac number, because 81067731 - 2¹¹ = 81065683 is a prime.

It is a super-2 number, since 2×81067731² = 13143954018976722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81067692 and 81067701.

It is not an unprimeable number, because it can be changed into a prime (81067733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30660 + ... + 33198.

It is an arithmetic number, because the mean of its divisors is an integer number (7010400).

Almost surely, 2^81067731 is an apocalyptic number.

81067731 is a deficient number, since it is larger than the sum of its proper divisors (31098669).

81067731 is a wasteful number, since it uses less digits than its factorization.

81067731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2938.

The product of its (nonzero) digits is 7056, while the sum is 33.

The square root of 81067731 is about 9003.7620470557. The cubic root of 81067731 is about 432.7954362659.

The spelling of 81067731 in words is "eighty-one million, sixty-seven thousand, seven hundred thirty-one".