81458866 has 8 divisors (see below), whose sum is σ = 129375900. Its totient is φ = 38333568.

The previous prime is 81458863. The next prime is 81458873. The reversal of 81458866 is 66885418.

It can be written as a sum of positive squares in 2 ways, for example, as 79121025 + 2337841 = 8895^2 + 1529^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (81458863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1197891 + ... + 1197958.

Almost surely, 2^81458866 is an apocalyptic number.

81458866 is a deficient number, since it is larger than the sum of its proper divisors (47917034).

81458866 is a wasteful number, since it uses less digits than its factorization.

81458866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2395868.

The product of its digits is 368640, while the sum is 46.

The square root of 81458866 is about 9025.4565535490. The cubic root of 81458866 is about 433.4903692518.

The spelling of 81458866 in words is "eighty-one million, four hundred fifty-eight thousand, eight hundred sixty-six".