81465253632 has 720 divisors, whose sum is σ = 295997363200. Its totient is φ = 21767823360.

The previous prime is 81465253609. The next prime is 81465253637. The reversal of 81465253632 is 23635256418.

81465253632 is a `hidden beast` number, since 8 + 1 + 4 + 6 + 5 + 2 + 5 + 3 + 632 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81465253637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 300609657 + ... + 300609927.

Almost surely, 2^81465253632 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81465253632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147998681600).

81465253632 is an abundant number, since it is smaller than the sum of its proper divisors (214532109568).

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

81465253632 is a wasteful number, since it uses less digits than its factorization.

81465253632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 411 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The spelling of 81465253632 in words is "eighty-one billion, four hundred sixty-five million, two hundred fifty-three thousand, six hundred thirty-two".