668620020 has 24 divisors (see below), whose sum is σ = 1872136224. Its totient is φ = 178298656.

The previous prime is 668620009. The next prime is 668620039. The reversal of 668620020 is 20026866.

It is a super-2 number, since 2×668620020² = 894105462289600800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 668620020.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5571774 + ... + 5571893.

It is an arithmetic number, because the mean of its divisors is an integer number (78005676).

Almost surely, 2^668620020 is an apocalyptic number.

668620020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

668620020 is an abundant number, since it is smaller than the sum of its proper divisors (1203516204).

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

668620020 is a wasteful number, since it uses less digits than its factorization.

668620020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11143679 (or 11143677 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 668620020 is about 25857.6878316682. The cubic root of 668620020 is about 874.4328384404.

Adding to 668620020 its reverse (20026866), we get a palindrome (688646886).

The spelling of 668620020 in words is "six hundred sixty-eight million, six hundred twenty thousand, twenty".