81458140 has 24 divisors (see below), whose sum is σ = 172987920. Its totient is φ = 32216448.

The previous prime is 81458123. The next prime is 81458171. The reversal of 81458140 is 4185418.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21102 + ... + 24661.

It is an arithmetic number, because the mean of its divisors is an integer number (7207830).

Almost surely, 2^81458140 is an apocalyptic number.

It is an amenable number.

81458140 is an abundant number, since it is smaller than the sum of its proper divisors (91529780).

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

81458140 is a wasteful number, since it uses less digits than its factorization.

81458140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45861 (or 45859 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 31.

The square root of 81458140 is about 9025.4163338873. The cubic root of 81458140 is about 433.4890814241.

The spelling of 81458140 in words is "eighty-one million, four hundred fifty-eight thousand, one hundred forty".