81071193 has 16 divisors (see below), whose sum is σ = 126167040. Its totient is φ = 45340176.

The previous prime is 81071191. The next prime is 81071203. The reversal of 81071193 is 39117018.

It is not a de Polignac number, because 81071193 - 2¹ = 81071191 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81071193.

It is not an unprimeable number, because it can be changed into a prime (81071191) 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, 40083 + ... + 42056.

It is an arithmetic number, because the mean of its divisors is an integer number (7885440).

Almost surely, 2^81071193 is an apocalyptic number.

It is an amenable number.

81071193 is a deficient number, since it is larger than the sum of its proper divisors (45095847).

81071193 is a wasteful number, since it uses less digits than its factorization.

81071193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82196.

The product of its (nonzero) digits is 1512, while the sum is 30.

The square root of 81071193 is about 9003.9542979738. The cubic root of 81071193 is about 432.8015970258.

The spelling of 81071193 in words is "eighty-one million, seventy-one thousand, one hundred ninety-three".