81518078 has 8 divisors (see below), whose sum is σ = 123952368. Its totient is φ = 40200624.

The previous prime is 81518071. The next prime is 81518083. The reversal of 81518078 is 87081518.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81518071) 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, 279026 + ... + 279317.

It is an arithmetic number, because the mean of its divisors is an integer number (15494046).

Almost surely, 2^81518078 is an apocalyptic number.

81518078 is a deficient number, since it is larger than the sum of its proper divisors (42434290).

81518078 is a wasteful number, since it uses less digits than its factorization.

81518078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558418.

The product of its (nonzero) digits is 17920, while the sum is 38.

The square root of 81518078 is about 9028.7362349334. The cubic root of 81518078 is about 433.5953777313.

The spelling of 81518078 in words is "eighty-one million, five hundred eighteen thousand, seventy-eight".