7781082666 has 32 divisors (see below), whose sum is σ = 18558609408. Its totient is φ = 2126506800.

The previous prime is 7781082649. The next prime is 7781082671. The reversal of 7781082666 is 6662801877.

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, 4026510 + ... + 4028441.

It is an arithmetic number, because the mean of its divisors is an integer number (579956544).

Almost surely, 2^7781082666 is an apocalyptic number.

7781082666 is an abundant number, since it is smaller than the sum of its proper divisors (10777526742).

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

7781082666 is a wasteful number, since it uses less digits than its factorization.

7781082666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8054986.

The product of its (nonzero) digits is 1354752, while the sum is 51.

The square root of 7781082666 is about 88210.4453338719. The cubic root of 7781082666 is about 1981.5879063873.

The spelling of 7781082666 in words is "seven billion, seven hundred eighty-one million, eighty-two thousand, six hundred sixty-six".