81668130 has 32 divisors (see below), whose sum is σ = 196487424. Its totient is φ = 21724416.

The previous prime is 81668129. The next prime is 81668149. The reversal of 81668130 is 3186618.

It is a junction number, because it is equal to n+sod(n) for n = 81668091 and 81668100.

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, 9847 + ... + 16133.

It is an arithmetic number, because the mean of its divisors is an integer number (6140232).

Almost surely, 2^81668130 is an apocalyptic number.

81668130 is an abundant number, since it is smaller than the sum of its proper divisors (114819294).

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

81668130 is a wasteful number, since it uses less digits than its factorization.

81668130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6730.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 81668130 is about 9037.0421045827. The cubic root of 81668130 is about 433.8612572996.

The spelling of 81668130 in words is "eighty-one million, six hundred sixty-eight thousand, one hundred thirty".