81731585952 has 48 divisors (see below), whose sum is σ = 238383794880. Its totient is φ = 27243861696.

The previous prime is 81731585909. The next prime is 81731585977. The reversal of 81731585952 is 25958513718.

81731585952 is a `hidden beast` number, since 8 + 1 + 7 + 3 + 1 + 585 + 9 + 52 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-3 number, since 3×81731585952³ (a number of 34 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 47297508 + ... + 47299235.

It is an arithmetic number, because the mean of its divisors is an integer number (4966329060).

Almost surely, 2^81731585952 is an apocalyptic number.

It is an amenable number.

81731585952 is an abundant number, since it is smaller than the sum of its proper divisors (156652208928).

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

81731585952 is a wasteful number, since it uses less digits than its factorization.

81731585952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94596762 (or 94596748 counting only the distinct ones).

The product of its digits is 3024000, while the sum is 54.

The spelling of 81731585952 in words is "eighty-one billion, seven hundred thirty-one million, five hundred eighty-five thousand, nine hundred fifty-two".