81773250666 has 32 divisors (see below), whose sum is σ = 166696040448. Its totient is φ = 26733220800.

The previous prime is 81773250649. The next prime is 81773250667. The reversal of 81773250666 is 66605237718.

It is not an unprimeable number, because it can be changed into a prime (81773250667) 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 15 ways as a sum of consecutive naturals, for example, 806616 + ... + 902316.

It is an arithmetic number, because the mean of its divisors is an integer number (5209251264).

Almost surely, 2^81773250666 is an apocalyptic number.

81773250666 is an abundant number, since it is smaller than the sum of its proper divisors (84922789782).

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

81773250666 is a wasteful number, since it uses less digits than its factorization.

81773250666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98446.

The product of its (nonzero) digits is 2540160, while the sum is 51.

The spelling of 81773250666 in words is "eighty-one billion, seven hundred seventy-three million, two hundred fifty thousand, six hundred sixty-six".