81870118 has 16 divisors (see below), whose sum is σ = 135202320. Its totient is φ = 36871200.

The previous prime is 81870109. The next prime is 81870119. The reversal of 81870118 is 81107818.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81870119) 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 7 ways as a sum of consecutive naturals, for example, 14673 + ... + 19468.

It is an arithmetic number, because the mean of its divisors is an integer number (8450145).

Almost surely, 2^81870118 is an apocalyptic number.

81870118 is a deficient number, since it is larger than the sum of its proper divisors (53332202).

81870118 is a wasteful number, since it uses less digits than its factorization.

81870118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34263.

The product of its (nonzero) digits is 3584, while the sum is 34.

The square root of 81870118 is about 9048.2107623552. The cubic root of 81870118 is about 434.2186493380.

The spelling of 81870118 in words is "eighty-one million, eight hundred seventy thousand, one hundred eighteen".