81458984 has 8 divisors (see below), whose sum is σ = 152735610. Its totient is φ = 40729488.

The previous prime is 81458983. The next prime is 81458987. The reversal of 81458984 is 48985418.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 81396484 + 62500 = 9022^2 + 250^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-5 number, since 5×81458984⁵ (a number of 41 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (81458983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5091179 + ... + 5091194.

Almost surely, 2^81458984 is an apocalyptic number.

It is an amenable number.

81458984 is a deficient number, since it is larger than the sum of its proper divisors (71276626).

81458984 is a wasteful number, since it uses less digits than its factorization.

81458984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10182379 (or 10182375 counting only the distinct ones).

The product of its digits is 368640, while the sum is 47.

The square root of 81458984 is about 9025.4630906120. The cubic root of 81458984 is about 433.4905785674.

The spelling of 81458984 in words is "eighty-one million, four hundred fifty-eight thousand, nine hundred eighty-four".