81827740 has 24 divisors (see below), whose sum is σ = 172225872. Its totient is φ = 32657280.

The previous prime is 81827731. The next prime is 81827741. The reversal of 81827740 is 4772818.

It is a self number, because there is not a number n which added to its sum of digits gives 81827740.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81827741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4960 + ... + 13720.

It is an arithmetic number, because the mean of its divisors is an integer number (7176078).

Almost surely, 2^81827740 is an apocalyptic number.

It is an amenable number.

81827740 is an abundant number, since it is smaller than the sum of its proper divisors (90398132).

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

81827740 is a wasteful number, since it uses less digits than its factorization.

81827740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9237 (or 9235 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 37.

The square root of 81827740 is about 9045.8686702826. The cubic root of 81827740 is about 434.1437156330.

The spelling of 81827740 in words is "eighty-one million, eight hundred twenty-seven thousand, seven hundred forty".