81087818 has 8 divisors (see below), whose sum is σ = 139007712. Its totient is φ = 34751916.

The previous prime is 81087817. The next prime is 81087859. The reversal of 81087818 is 81878018.

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

It is a super-2 number, since 2×81087818² = 13150468456002248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81087817) 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 3 ways as a sum of consecutive naturals, for example, 2895980 + ... + 2896007.

It is an arithmetic number, because the mean of its divisors is an integer number (17375964).

Almost surely, 2^81087818 is an apocalyptic number.

81087818 is a deficient number, since it is larger than the sum of its proper divisors (57919894).

81087818 is a wasteful number, since it uses less digits than its factorization.

81087818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5791996.

The product of its (nonzero) digits is 28672, while the sum is 41.

The square root of 81087818 is about 9004.8774561345. The cubic root of 81087818 is about 432.8311793986.

The spelling of 81087818 in words is "eighty-one million, eighty-seven thousand, eight hundred eighteen".