668881047 has 4 divisors (see below), whose sum is σ = 891841400. Its totient is φ = 445920696.

The previous prime is 668881019. The next prime is 668881049. The reversal of 668881047 is 740188866.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 668881047 - 2¹⁴ = 668864663 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668880987 and 668881005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668881049) 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 3 ways as a sum of consecutive naturals, for example, 111480172 + ... + 111480177.

It is an arithmetic number, because the mean of its divisors is an integer number (222960350).

Almost surely, 2^668881047 is an apocalyptic number.

668881047 is a deficient number, since it is larger than the sum of its proper divisors (222960353).

668881047 is a wasteful number, since it uses less digits than its factorization.

668881047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222960352.

The product of its (nonzero) digits is 516096, while the sum is 48.

The square root of 668881047 is about 25862.7347161896. The cubic root of 668881047 is about 874.5466155123.

The spelling of 668881047 in words is "six hundred sixty-eight million, eight hundred eighty-one thousand, forty-seven".