81898694 has 8 divisors (see below), whose sum is σ = 122888448. Its totient is φ = 40935880.

The previous prime is 81898693. The next prime is 81898777. The reversal of 81898694 is 49689818.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81898693) 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 3 ways as a sum of consecutive naturals, for example, 4859 + ... + 13689.

It is an arithmetic number, because the mean of its divisors is an integer number (15361056).

Almost surely, 2^81898694 is an apocalyptic number.

81898694 is a deficient number, since it is larger than the sum of its proper divisors (40989754).

81898694 is a wasteful number, since it uses less digits than its factorization.

81898694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13470.

The product of its digits is 995328, while the sum is 53.

The square root of 81898694 is about 9049.7897213140. The cubic root of 81898694 is about 434.2691634493.

The spelling of 81898694 in words is "eighty-one million, eight hundred ninety-eight thousand, six hundred ninety-four".