81559898 has 16 divisors (see below), whose sum is σ = 142456320. Its totient is φ = 34294416.

The previous prime is 81559873. The next prime is 81559939. The reversal of 81559898 is 89895518.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54218 + ... + 55701.

It is an arithmetic number, because the mean of its divisors is an integer number (8903520).

Almost surely, 2^81559898 is an apocalyptic number.

81559898 is a deficient number, since it is larger than the sum of its proper divisors (60896422).

81559898 is a wasteful number, since it uses less digits than its factorization.

81559898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109981.

The product of its digits is 1036800, while the sum is 53.

The square root of 81559898 is about 9031.0518767196. The cubic root of 81559898 is about 433.6695120387.

The spelling of 81559898 in words is "eighty-one million, five hundred fifty-nine thousand, eight hundred ninety-eight".