81537258 has 32 divisors (see below), whose sum is σ = 180564480. Its totient is φ = 24338160.

The previous prime is 81537257. The next prime is 81537263. The reversal of 81537258 is 85273518.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81537257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4798 + ... + 13641.

It is an arithmetic number, because the mean of its divisors is an integer number (5642640).

Almost surely, 2^81537258 is an apocalyptic number.

81537258 is an abundant number, since it is smaller than the sum of its proper divisors (99027222).

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

81537258 is a wasteful number, since it uses less digits than its factorization.

81537258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18522.

The product of its digits is 67200, while the sum is 39.

The square root of 81537258 is about 9029.7983366186. The cubic root of 81537258 is about 433.6293812611.

The spelling of 81537258 in words is "eighty-one million, five hundred thirty-seven thousand, two hundred fifty-eight".