81205632 has 64 divisors (see below), whose sum is σ = 239679600. Its totient is φ = 27067392.

The previous prime is 81205627. The next prime is 81205633. The reversal of 81205632 is 23650218.

81205632 is a `hidden beast` number, since 8 + 1 + 20 + 5 + 632 = 666.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81205596 and 81205605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81205633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8293 + ... + 15204.

Almost surely, 2^81205632 is an apocalyptic number.

It is an amenable number.

81205632 is an abundant number, since it is smaller than the sum of its proper divisors (158473968).

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

81205632 is a wasteful number, since it uses less digits than its factorization.

81205632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23520 (or 23502 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 81205632 is about 9011.4167587566. The cubic root of 81205632 is about 433.0407007843.

The spelling of 81205632 in words is "eighty-one million, two hundred five thousand, six hundred thirty-two".