81499418 has 32 divisors (see below), whose sum is σ = 164142720. Its totient is φ = 29309760.

The previous prime is 81499399. The next prime is 81499427.

81499418 is nontrivially palindromic in base 10.

It is a super-3 number, since 3×81499418³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18353 + ... + 22356.

It is an arithmetic number, because the mean of its divisors is an integer number (5129460).

Almost surely, 2^81499418 is an apocalyptic number.

81499418 is an abundant number, since it is smaller than the sum of its proper divisors (82643302).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81499418 is a wasteful number, since it uses less digits than its factorization.

81499418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40742.

The product of its digits is 82944, while the sum is 44.

The square root of 81499418 is about 9027.7028085776. The cubic root of 81499418 is about 433.5622909716.

The spelling of 81499418 in words is "eighty-one million, four hundred ninety-nine thousand, four hundred eighteen".