81532918 has 8 divisors (see below), whose sum is σ = 129493512. Its totient is φ = 38368416.

The previous prime is 81532909. The next prime is 81532937. The reversal of 81532918 is 81923518.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1198980 + ... + 1199047.

It is an arithmetic number, because the mean of its divisors is an integer number (16186689).

Almost surely, 2^81532918 is an apocalyptic number.

81532918 is a deficient number, since it is larger than the sum of its proper divisors (47960594).

81532918 is a wasteful number, since it uses less digits than its factorization.

81532918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2398046.

The product of its digits is 17280, while the sum is 37.

The square root of 81532918 is about 9029.5580179763. The cubic root of 81532918 is about 433.6216874986.

It can be divided in two parts, 815 and 32918, that added together give a palindrome (33733).

The spelling of 81532918 in words is "eighty-one million, five hundred thirty-two thousand, nine hundred eighteen".