81358158 has 32 divisors (see below), whose sum is σ = 196902144. Its totient is φ = 21877632.

The previous prime is 81358157. The next prime is 81358159. The reversal of 81358158 is 85185318.

It is an interprime number because it is at equal distance from previous prime (81358157) and next prime (81358159).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81358157) 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, 56260 + ... + 57687.

It is an arithmetic number, because the mean of its divisors is an integer number (6153192).

Almost surely, 2^81358158 is an apocalyptic number.

81358158 is an abundant number, since it is smaller than the sum of its proper divisors (115543986).

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

81358158 is a wasteful number, since it uses less digits than its factorization.

81358158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113976.

The product of its digits is 38400, while the sum is 39.

The square root of 81358158 is about 9019.8757197647. The cubic root of 81358158 is about 433.3116534847.

The spelling of 81358158 in words is "eighty-one million, three hundred fifty-eight thousand, one hundred fifty-eight".