668777851 has 4 divisors (see below), whose sum is σ = 764317552. Its totient is φ = 573238152.

The previous prime is 668777833. The next prime is 668777929. The reversal of 668777851 is 158777866.

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 668777851 - 2⁵ = 668777819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668777792 and 668777801.

It is not an unprimeable number, because it can be changed into a prime (668777251) 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, 47769840 + ... + 47769853.

It is an arithmetic number, because the mean of its divisors is an integer number (191079388).

Almost surely, 2^668777851 is an apocalyptic number.

668777851 is a deficient number, since it is larger than the sum of its proper divisors (95539701).

668777851 is an equidigital number, since it uses as much as digits as its factorization.

668777851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95539700.

The product of its digits is 3951360, while the sum is 55.

The square root of 668777851 is about 25860.7395679242. The cubic root of 668777851 is about 874.5016377320.

The spelling of 668777851 in words is "six hundred sixty-eight million, seven hundred seventy-seven thousand, eight hundred fifty-one".