668029940 has 48 divisors (see below), whose sum is σ = 1497944448. Its totient is φ = 249642624.

The previous prime is 668029939. The next prime is 668029951. The reversal of 668029940 is 49920866.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 668029891 and 668029900.

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 15 ways as a sum of consecutive naturals, for example, 2894 + ... + 36666.

It is an arithmetic number, because the mean of its divisors is an integer number (31207176).

Almost surely, 2^668029940 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668029940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748972224).

668029940 is an abundant number, since it is smaller than the sum of its proper divisors (829914508).

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

668029940 is a wasteful number, since it uses less digits than its factorization.

668029940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33848 (or 33846 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 668029940 is about 25846.2751668398. The cubic root of 668029940 is about 874.1755237824.

The spelling of 668029940 in words is "six hundred sixty-eight million, twenty-nine thousand, nine hundred forty".