81903118 has 16 divisors (see below), whose sum is σ = 134202240. Its totient is φ = 37179000.

The previous prime is 81903113. The next prime is 81903131. The reversal of 81903118 is 81130918.

It is a self number, because there is not a number n which added to its sum of digits gives 81903118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81903113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18193 + ... + 22243.

It is an arithmetic number, because the mean of its divisors is an integer number (8387640).

Almost surely, 2^81903118 is an apocalyptic number.

81903118 is a deficient number, since it is larger than the sum of its proper divisors (52299122).

81903118 is a wasteful number, since it uses less digits than its factorization.

81903118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4983.

The product of its (nonzero) digits is 1728, while the sum is 31.

The square root of 81903118 is about 9050.0341435820. The cubic root of 81903118 is about 434.2769827526.

The spelling of 81903118 in words is "eighty-one million, nine hundred three thousand, one hundred eighteen".