81593865988 has 12 divisors (see below), whose sum is σ = 143220655312. Its totient is φ = 40673678760.

The previous prime is 81593865971. The next prime is 81593866007. The reversal of 81593865988 is 88956839518.

It is a super-3 number, since 3×81593865988³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30812070 + ... + 30814717.

Almost surely, 2^81593865988 is an apocalyptic number.

It is an amenable number.

81593865988 is a deficient number, since it is larger than the sum of its proper divisors (61626789324).

81593865988 is a wasteful number, since it uses less digits than its factorization.

81593865988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61627122 (or 61627120 counting only the distinct ones).

The product of its digits is 149299200, while the sum is 70.

The spelling of 81593865988 in words is "eighty-one billion, five hundred ninety-three million, eight hundred sixty-five thousand, nine hundred eighty-eight".