81159498 has 24 divisors (see below), whose sum is σ = 200966688. Its totient is φ = 23188392.

The previous prime is 81159497. The next prime is 81159509. The reversal of 81159498 is 89495118.

81159498 is a `hidden beast` number, since 8 + 1 + 159 + 498 = 666.

It is a super-2 number, since 2×81159498² = 13173728231224008, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81159497) 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 11 ways as a sum of consecutive naturals, for example, 321936 + ... + 322187.

It is an arithmetic number, because the mean of its divisors is an integer number (8373612).

Almost surely, 2^81159498 is an apocalyptic number.

81159498 is an abundant number, since it is smaller than the sum of its proper divisors (119807190).

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

81159498 is a wasteful number, since it uses less digits than its factorization.

81159498 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644138 (or 644135 counting only the distinct ones).

The product of its digits is 103680, while the sum is 45.

The square root of 81159498 is about 9008.8566422160. The cubic root of 81159498 is about 432.9586798554.

The spelling of 81159498 in words is "eighty-one million, one hundred fifty-nine thousand, four hundred ninety-eight".