668867845 has 4 divisors (see below), whose sum is σ = 802641420. Its totient is φ = 535094272.

The previous prime is 668867821. The next prime is 668867851. The reversal of 668867845 is 548768866.

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 386594244 + 282273601 = 19662^2 + 16801^2 .

It is a cyclic number.

It is not a de Polignac number, because 668867845 - 2⁵ = 668867813 is a prime.

It is a super-3 number, since 3×668867845³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 668867845.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66886780 + ... + 66886789.

It is an arithmetic number, because the mean of its divisors is an integer number (200660355).

Almost surely, 2^668867845 is an apocalyptic number.

It is an amenable number.

668867845 is a deficient number, since it is larger than the sum of its proper divisors (133773575).

668867845 is a wasteful number, since it uses less digits than its factorization.

668867845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133773574.

The product of its digits is 15482880, while the sum is 58.

The square root of 668867845 is about 25862.4794828338. The cubic root of 668867845 is about 874.5408617038.

The spelling of 668867845 in words is "six hundred sixty-eight million, eight hundred sixty-seven thousand, eight hundred forty-five".