81093506 has 16 divisors (see below), whose sum is σ = 132298488. Its totient is φ = 37056000.

The previous prime is 81093503. The next prime is 81093511. The reversal of 81093506 is 60539018.

It can be written as a sum of positive squares in 4 ways, for example, as 81090025 + 3481 = 9005^2 + 59^2 .

It is not an unprimeable number, because it can be changed into a prime (81093503) 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, 12815 + ... + 18066.

Almost surely, 2^81093506 is an apocalyptic number.

81093506 is a deficient number, since it is larger than the sum of its proper divisors (51204982).

81093506 is a wasteful number, since it uses less digits than its factorization.

81093506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30997.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 81093506 is about 9005.1932794360. The cubic root of 81093506 is about 432.8412996454.

The spelling of 81093506 in words is "eighty-one million, ninety-three thousand, five hundred six".