81559802 has 8 divisors (see below), whose sum is σ = 122380212. Its totient is φ = 40766400.

The previous prime is 81559789. The next prime is 81559811. The reversal of 81559802 is 20895518.

It can be written as a sum of positive squares in 2 ways, for example, as 81558961 + 841 = 9031^2 + 29^2 .

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

It is an unprimeable number.

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, 4652 + ... + 13592.

Almost surely, 2^81559802 is an apocalyptic number.

81559802 is a deficient number, since it is larger than the sum of its proper divisors (40820410).

81559802 is a wasteful number, since it uses less digits than its factorization.

81559802 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13504.

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 81559802 is about 9031.0465617225. The cubic root of 81559802 is about 433.6693418885.

The spelling of 81559802 in words is "eighty-one million, five hundred fifty-nine thousand, eight hundred two".