668794477 has 4 divisors (see below), whose sum is σ = 720240220. Its totient is φ = 617348736.

The previous prime is 668794463. The next prime is 668794493. The reversal of 668794477 is 774497866.

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 367910761 + 300883716 = 19181^2 + 17346^2 .

It is a cyclic number.

It is not a de Polignac number, because 668794477 - 2¹¹ = 668792429 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 (668794447) 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, 25722852 + ... + 25722877.

It is an arithmetic number, because the mean of its divisors is an integer number (180060055).

Almost surely, 2^668794477 is an apocalyptic number.

It is an amenable number.

668794477 is a deficient number, since it is larger than the sum of its proper divisors (51445743).

668794477 is a wasteful number, since it uses less digits than its factorization.

668794477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51445742.

The product of its digits is 14224896, while the sum is 58.

The square root of 668794477 is about 25861.0610184501. The cubic root of 668794477 is about 874.5088844552.

The spelling of 668794477 in words is "six hundred sixty-eight million, seven hundred ninety-four thousand, four hundred seventy-seven".