81361152 has 144 divisors (see below), whose sum is σ = 245280000. Its totient is φ = 26597376.

The previous prime is 81361141. The next prime is 81361157. The reversal of 81361152 is 25116318.

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

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

It is not an unprimeable number, because it can be changed into a prime (81361157) 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 15 ways as a sum of consecutive naturals, for example, 545974 + ... + 546122.

Almost surely, 2^81361152 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 81361152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122640000).

81361152 is an abundant number, since it is smaller than the sum of its proper divisors (163918848).

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

81361152 is a wasteful number, since it uses less digits than its factorization.

81361152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 233 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 81361152 is about 9020.0416850478. The cubic root of 81361152 is about 433.3169687443.

The spelling of 81361152 in words is "eighty-one million, three hundred sixty-one thousand, one hundred fifty-two".