81478293 has 16 divisors (see below), whose sum is σ = 118601280. Its totient is φ = 49451904.

The previous prime is 81478279. The next prime is 81478301. The reversal of 81478293 is 39287418.

It is a de Polignac number, because none of the positive numbers 2^k-81478293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81478223) 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, 11463 + ... + 17156.

It is an arithmetic number, because the mean of its divisors is an integer number (7412580).

Almost surely, 2^81478293 is an apocalyptic number.

It is an amenable number.

81478293 is a deficient number, since it is larger than the sum of its proper divisors (37122987).

81478293 is a wasteful number, since it uses less digits than its factorization.

81478293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28708.

The product of its digits is 96768, while the sum is 42.

The square root of 81478293 is about 9026.5327230338. The cubic root of 81478293 is about 433.5248273304.

The spelling of 81478293 in words is "eighty-one million, four hundred seventy-eight thousand, two hundred ninety-three".