668771387 has 4 divisors (see below), whose sum is σ = 672507720. Its totient is φ = 665035056.

The previous prime is 668771333. The next prime is 668771423. The reversal of 668771387 is 783177866.

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

It is a cyclic number.

It is not a de Polignac number, because 668771387 - 2¹² = 668767291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668771087) 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, 1867898 + ... + 1868255.

It is an arithmetic number, because the mean of its divisors is an integer number (168126930).

Almost surely, 2^668771387 is an apocalyptic number.

668771387 is a deficient number, since it is larger than the sum of its proper divisors (3736333).

668771387 is a wasteful number, since it uses less digits than its factorization.

668771387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3736332.

The product of its digits is 2370816, while the sum is 53.

The square root of 668771387 is about 25860.6145905313. The cubic root of 668771387 is about 874.4988202560.

The spelling of 668771387 in words is "six hundred sixty-eight million, seven hundred seventy-one thousand, three hundred eighty-seven".