668888890 has 8 divisors (see below), whose sum is σ = 1204000020. Its totient is φ = 267555552.

The previous prime is 668888887. The next prime is 668888903. The reversal of 668888890 is 98888866.

It can be written as a sum of positive squares in 2 ways, for example, as 665794809 + 3094081 = 25803^2 + 1759^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 33444435 + ... + 33444454.

Almost surely, 2^668888890 is an apocalyptic number.

668888890 is a deficient number, since it is larger than the sum of its proper divisors (535111130).

668888890 is a wasteful number, since it uses less digits than its factorization.

668888890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66888896.

The product of its (nonzero) digits is 10616832, while the sum is 61.

The square root of 668888890 is about 25862.8863431752. The cubic root of 668888890 is about 874.5500336797.

The spelling of 668888890 in words is "six hundred sixty-eight million, eight hundred eighty-eight thousand, eight hundred ninety".