668695268544 has 224 divisors, whose sum is σ = 1911514429440. Its totient is φ = 205675008000.

The previous prime is 668695268443. The next prime is 668695268557. The reversal of 668695268544 is 445862596866.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 284428969 + ... + 284431319.

It is an arithmetic number, because the mean of its divisors is an integer number (8533546560).

Almost surely, 2^668695268544 is an apocalyptic number.

668695268544 is a gapful number since it is divisible by the number (64) 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 668695268544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (955757214720).

668695268544 is an abundant number, since it is smaller than the sum of its proper divisors (1242819160896).

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

668695268544 is a wasteful number, since it uses less digits than its factorization.

668695268544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4639 (or 4629 counting only the distinct ones).

The product of its digits is 597196800, while the sum is 69.

The spelling of 668695268544 in words is "six hundred sixty-eight billion, six hundred ninety-five million, two hundred sixty-eight thousand, five hundred forty-four".