81698158 has 32 divisors (see below), whose sum is σ = 134447040. Its totient is φ = 37079040.

The previous prime is 81698131. The next prime is 81698161. The reversal of 81698158 is 85189618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143298 + ... + 143866.

It is an arithmetic number, because the mean of its divisors is an integer number (4201470).

Almost surely, 2^81698158 is an apocalyptic number.

81698158 is a deficient number, since it is larger than the sum of its proper divisors (52748882).

81698158 is a wasteful number, since it uses less digits than its factorization.

81698158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732.

The product of its digits is 138240, while the sum is 46.

The square root of 81698158 is about 9038.7033362092. The cubic root of 81698158 is about 433.9144252834.

The spelling of 81698158 in words is "eighty-one million, six hundred ninety-eight thousand, one hundred fifty-eight".