668154877 has 4 divisors (see below), whose sum is σ = 719551420. Its totient is φ = 616758336.

The previous prime is 668154857. The next prime is 668154947. The reversal of 668154877 is 778451866.

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

It can be written as a sum of positive squares in 2 ways, for example, as 360468196 + 307686681 = 18986^2 + 17541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-668154877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668154827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25698252 + ... + 25698277.

It is an arithmetic number, because the mean of its divisors is an integer number (179887855).

Almost surely, 2^668154877 is an apocalyptic number.

It is an amenable number.

668154877 is a deficient number, since it is larger than the sum of its proper divisors (51396543).

668154877 is a wasteful number, since it uses less digits than its factorization.

668154877 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51396542.

The product of its digits is 2257920, while the sum is 52.

The square root of 668154877 is about 25848.6919785122. The cubic root of 668154877 is about 874.2300173776.

The spelling of 668154877 in words is "six hundred sixty-eight million, one hundred fifty-four thousand, eight hundred seventy-seven".