668087851 has 4 divisors (see below), whose sum is σ = 689639104. Its totient is φ = 646536600.

The previous prime is 668087837. The next prime is 668087863. The reversal of 668087851 is 158780866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 158780866 = 2 ⋅79390433.

It is a cyclic number.

It is not a de Polignac number, because 668087851 - 2⁷ = 668087723 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 668087795 and 668087804.

It is not an unprimeable number, because it can be changed into a prime (668087801) 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, 10775580 + ... + 10775641.

It is an arithmetic number, because the mean of its divisors is an integer number (172409776).

Almost surely, 2^668087851 is an apocalyptic number.

668087851 is a deficient number, since it is larger than the sum of its proper divisors (21551253).

668087851 is a wasteful number, since it uses less digits than its factorization.

668087851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21551252.

The product of its (nonzero) digits is 645120, while the sum is 49.

The square root of 668087851 is about 25847.3954393862. The cubic root of 668087851 is about 874.2007835864.

The spelling of 668087851 in words is "six hundred sixty-eight million, eighty-seven thousand, eight hundred fifty-one".