668828245 has 4 divisors (see below), whose sum is σ = 802593900. Its totient is φ = 535062592.

The previous prime is 668828239. The next prime is 668828257. The reversal of 668828245 is 542828866.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 542828866 = 2 ⋅271414433.

It can be written as a sum of positive squares in 2 ways, for example, as 306040036 + 362788209 = 17494^2 + 19047^2 .

It is a cyclic number.

It is not a de Polignac number, because 668828245 - 2¹⁷ = 668697173 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 66882820 + ... + 66882829.

It is an arithmetic number, because the mean of its divisors is an integer number (200648475).

Almost surely, 2^668828245 is an apocalyptic number.

It is an amenable number.

668828245 is a deficient number, since it is larger than the sum of its proper divisors (133765655).

668828245 is a wasteful number, since it uses less digits than its factorization.

668828245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133765654.

The product of its digits is 1474560, while the sum is 49.

The square root of 668828245 is about 25861.7138836543. The cubic root of 668828245 is about 874.5236024391.

The spelling of 668828245 in words is "six hundred sixty-eight million, eight hundred twenty-eight thousand, two hundred forty-five".