668899680 has 96 divisors (see below), whose sum is σ = 2231004384. Its totient is φ = 167878656.

The previous prime is 668899667. The next prime is 668899687. The reversal of 668899680 is 86998866.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668899687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32827 + ... + 49146.

It is an arithmetic number, because the mean of its divisors is an integer number (23239629).

Almost surely, 2^668899680 is an apocalyptic number.

668899680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668899680 is an abundant number, since it is smaller than the sum of its proper divisors (1562104704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668899680 is a wasteful number, since it uses less digits than its factorization.

668899680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82008 (or 82000 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 60.

The square root of 668899680 is about 25863.0949424078. The cubic root of 668899680 is about 874.5547361768.

The spelling of 668899680 in words is "six hundred sixty-eight million, eight hundred ninety-nine thousand, six hundred eighty".