81948878 has 16 divisors (see below), whose sum is σ = 134245296. Its totient is φ = 37208640.

The previous prime is 81948869. The next prime is 81948883. The reversal of 81948878 is 87884918.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 28850 + ... + 31562.

It is an arithmetic number, because the mean of its divisors is an integer number (8390331).

Almost surely, 2^81948878 is an apocalyptic number.

81948878 is a deficient number, since it is larger than the sum of its proper divisors (52296418).

81948878 is a wasteful number, since it uses less digits than its factorization.

81948878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4099.

The product of its digits is 1032192, while the sum is 53.

The square root of 81948878 is about 9052.5619578106. The cubic root of 81948878 is about 434.3578458315.

The spelling of 81948878 in words is "eighty-one million, nine hundred forty-eight thousand, eight hundred seventy-eight".