6661905867 has 12 divisors (see below), whose sum is σ = 9635407704. Its totient is φ = 4435429920.

The previous prime is 6661905853. The next prime is 6661905937. The reversal of 6661905867 is 7685091666.

It is not a de Polignac number, because 6661905867 - 2¹⁹ = 6661381579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6661905667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 479493 + ... + 493190.

It is an arithmetic number, because the mean of its divisors is an integer number (802950642).

Almost surely, 2^6661905867 is an apocalyptic number.

6661905867 is a deficient number, since it is larger than the sum of its proper divisors (2973501837).

6661905867 is a wasteful number, since it uses less digits than its factorization.

6661905867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973450 (or 973447 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The square root of 6661905867 is about 81620.4990612040. The cubic root of 6661905867 is about 1881.6239426746.

The spelling of 6661905867 in words is "six billion, six hundred sixty-one million, nine hundred five thousand, eight hundred sixty-seven".