81929952 has 144 divisors (see below), whose sum is σ = 255003840. Its totient is φ = 24800256.

The previous prime is 81929927. The next prime is 81929963. The reversal of 81929952 is 25992918.

It is a tau number, because it is divible by the number of its divisors (144).

It is a junction number, because it is equal to n+sod(n) for n = 81929898 and 81929907.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 295638 + ... + 295914.

It is an arithmetic number, because the mean of its divisors is an integer number (1770860).

Almost surely, 2^81929952 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 81929952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127501920).

81929952 is an abundant number, since it is smaller than the sum of its proper divisors (173073888).

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

81929952 is a wasteful number, since it uses less digits than its factorization.

81929952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385 (or 374 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 81929952 is about 9051.5165580139. The cubic root of 81929952 is about 434.3244051072.

The spelling of 81929952 in words is "eighty-one million, nine hundred twenty-nine thousand, nine hundred fifty-two".