668822192640 has 2560 divisors, whose sum is σ = 3086339604480. Its totient is φ = 133772083200.

The previous prime is 668822192639. The next prime is 668822192663. The reversal of 668822192640 is 46291228866.

It is a tau number, because it is divible by the number of its divisors (2560).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 10964298210 + ... + 10964298270.

It is an arithmetic number, because the mean of its divisors is an integer number (1205601408).

Almost surely, 2^668822192640 is an apocalyptic number.

668822192640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668822192640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1543169802240).

668822192640 is an abundant number, since it is smaller than the sum of its proper divisors (2417517411840).

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

668822192640 is a wasteful number, since it uses less digits than its factorization.

668822192640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

It can be divided in two parts, 66882 and 2192640, that added together give a palindrome (2259522).

The spelling of 668822192640 in words is "six hundred sixty-eight billion, eight hundred twenty-two million, one hundred ninety-two thousand, six hundred forty".