81941140 has 12 divisors (see below), whose sum is σ = 172076436. Its totient is φ = 32776448.

The previous prime is 81941131. The next prime is 81941141. The reversal of 81941140 is 4114918.

It can be written as a sum of positive squares in 2 ways, for example, as 50893956 + 31047184 = 7134^2 + 5572^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81941099 and 81941108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81941141) 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 3 ways as a sum of consecutive naturals, for example, 2048509 + ... + 2048548.

It is an arithmetic number, because the mean of its divisors is an integer number (14339703).

Almost surely, 2^81941140 is an apocalyptic number.

It is an amenable number.

81941140 is an abundant number, since it is smaller than the sum of its proper divisors (90135296).

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

81941140 is a wasteful number, since it uses less digits than its factorization.

81941140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4097066 (or 4097064 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 81941140 is about 9052.1345548992. The cubic root of 81941140 is about 434.3441740283.

The spelling of 81941140 in words is "eighty-one million, nine hundred forty-one thousand, one hundred forty".