81788148 has 36 divisors (see below), whose sum is σ = 222646788. Its totient is φ = 25165440.

The previous prime is 81788123. The next prime is 81788171. The reversal of 81788148 is 84188718.

It can be written as a sum of positive squares in 2 ways, for example, as 6411024 + 75377124 = 2532^2 + 8682^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 86913 + ... + 87848.

It is an arithmetic number, because the mean of its divisors is an integer number (6184633).

Almost surely, 2^81788148 is an apocalyptic number.

It is an amenable number.

81788148 is an abundant number, since it is smaller than the sum of its proper divisors (140858640).

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

81788148 is a wasteful number, since it uses less digits than its factorization.

81788148 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174784 (or 174779 counting only the distinct ones).

The product of its digits is 114688, while the sum is 45.

The square root of 81788148 is about 9043.6800031845. The cubic root of 81788148 is about 434.0736848140.

The spelling of 81788148 in words is "eighty-one million, seven hundred eighty-eight thousand, one hundred forty-eight".