668643338 has 24 divisors (see below), whose sum is σ = 1125907776. Its totient is φ = 297457160.

The previous prime is 668643323. The next prime is 668643341. The reversal of 668643338 is 833346866.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a junction number, because it is equal to n+sod(n) for n = 668643292 and 668643301.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18020 + ... + 40767.

It is an arithmetic number, because the mean of its divisors is an integer number (46912824).

Almost surely, 2^668643338 is an apocalyptic number.

668643338 is a deficient number, since it is larger than the sum of its proper divisors (457264438).

668643338 is a wasteful number, since it uses less digits than its factorization.

668643338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58858 (or 58847 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 47.

The square root of 668643338 is about 25858.1387187864. The cubic root of 668643338 is about 874.4430035503.

The spelling of 668643338 in words is "six hundred sixty-eight million, six hundred forty-three thousand, three hundred thirty-eight".