81093131 has 4 divisors (see below), whose sum is σ = 92677872. Its totient is φ = 69508392.

The previous prime is 81093119. The next prime is 81093137. The reversal of 81093131 is 13139018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81093131 - 2²² = 76898827 is a prime.

It is a super-2 number, since 2×81093131² = 13152191790766322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81093131.

It is not an unprimeable number, because it can be changed into a prime (81093137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5792360 + ... + 5792373.

It is an arithmetic number, because the mean of its divisors is an integer number (23169468).

Almost surely, 2^81093131 is an apocalyptic number.

81093131 is a deficient number, since it is larger than the sum of its proper divisors (11584741).

81093131 is a wasteful number, since it uses less digits than its factorization.

81093131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11584740.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 81093131 is about 9005.1724580932. The cubic root of 81093131 is about 432.8406324496.

The spelling of 81093131 in words is "eighty-one million, ninety-three thousand, one hundred thirty-one".