81138306 has 16 divisors (see below), whose sum is σ = 162388800. Its totient is φ = 27027408.

The previous prime is 81138301. The next prime is 81138307. The reversal of 81138306 is 60383118.

It is not an unprimeable number, because it can be changed into a prime (81138301) 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, 6955 + ... + 14513.

It is an arithmetic number, because the mean of its divisors is an integer number (10149300).

Almost surely, 2^81138306 is an apocalyptic number.

81138306 is an abundant number, since it is smaller than the sum of its proper divisors (81250494).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81138306 is a wasteful number, since it uses less digits than its factorization.

81138306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9353.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 81138306 is about 9007.6803895343. The cubic root of 81138306 is about 432.9209925060.

The spelling of 81138306 in words is "eighty-one million, one hundred thirty-eight thousand, three hundred six".