668153540 has 48 divisors (see below), whose sum is σ = 1458992640. Its totient is φ = 256746240.

The previous prime is 668153539. The next prime is 668153543. The reversal of 668153540 is 45351866.

668153540 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 668153494 and 668153503.

It is not an unprimeable number, because it can be changed into a prime (668153543) 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, 82304 + ... + 90056.

It is an arithmetic number, because the mean of its divisors is an integer number (30395680).

Almost surely, 2^668153540 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 668153540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (729496320).

668153540 is an abundant number, since it is smaller than the sum of its proper divisors (790839100).

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

668153540 is a wasteful number, since it uses less digits than its factorization.

668153540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7932 (or 7930 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 38.

The square root of 668153540 is about 25848.6661164556. Note that the first 3 decimals coincide. The cubic root of 668153540 is about 874.2294342562.

The spelling of 668153540 in words is "six hundred sixty-eight million, one hundred fifty-three thousand, five hundred forty".