81042178840 has 64 divisors (see below), whose sum is σ = 208731283200. Its totient is φ = 27740942208.

The previous prime is 81042178829. The next prime is 81042178871. The reversal of 81042178840 is 4887124018.

It is a super-2 number, since 2×81042178840² (a number of 23 digits) contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 60474 + ... + 407113.

It is an arithmetic number, because the mean of its divisors is an integer number (3261426300).

Almost surely, 2^81042178840 is an apocalyptic number.

It is an amenable number.

81042178840 is an abundant number, since it is smaller than the sum of its proper divisors (127689104360).

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

81042178840 is a wasteful number, since it uses less digits than its factorization.

81042178840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468224 (or 468220 counting only the distinct ones).

The product of its (nonzero) digits is 114688, while the sum is 43.

The spelling of 81042178840 in words is "eighty-one billion, forty-two million, one hundred seventy-eight thousand, eight hundred forty".