81541140 has 48 divisors (see below), whose sum is σ = 232068480. Its totient is φ = 21386880.

The previous prime is 81541133. The next prime is 81541151. The reversal of 81541140 is 4114518.

It is a self number, because there is not a number n which added to its sum of digits gives 81541140.

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 15 ways as a sum of consecutive naturals, for example, 7480 + ... + 14799.

It is an arithmetic number, because the mean of its divisors is an integer number (4834760).

Almost surely, 2^81541140 is an apocalyptic number.

It is an amenable number.

81541140 is an abundant number, since it is smaller than the sum of its proper divisors (150527340).

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

81541140 is a wasteful number, since it uses less digits than its factorization.

81541140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22352 (or 22350 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 81541140 is about 9030.0132890268. The cubic root of 81541140 is about 433.6362628700.

Adding to 81541140 its reverse (4114518), we get a palindrome (85655658).

The spelling of 81541140 in words is "eighty-one million, five hundred forty-one thousand, one hundred forty".