81608568225 has 12 divisors (see below), whose sum is σ = 134926166256. Its totient is φ = 43524569680.

The previous prime is 81608568199. The next prime is 81608568233. The reversal of 81608568225 is 52286580618.

It is not a de Polignac number, because 81608568225 - 2⁶ = 81608568161 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 544057047 + ... + 544057196.

It is an arithmetic number, because the mean of its divisors is an integer number (11243847188).

Almost surely, 2^81608568225 is an apocalyptic number.

It is an amenable number.

81608568225 is a deficient number, since it is larger than the sum of its proper divisors (53317598031).

81608568225 is a wasteful number, since it uses less digits than its factorization.

81608568225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1088114256 (or 1088114251 counting only the distinct ones).

The product of its (nonzero) digits is 1843200, while the sum is 51.

The spelling of 81608568225 in words is "eighty-one billion, six hundred eight million, five hundred sixty-eight thousand, two hundred twenty-five".