667557313920 has 896 divisors, whose sum is σ = 2853756195840. Its totient is φ = 145933996032.

The previous prime is 667557313883. The next prime is 667557313991. The reversal of 667557313920 is 29313755766.

667557313920 is a `hidden beast` number, since 6 + 6 + 7 + 557 + 31 + 39 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (896).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 75111717 + ... + 75120603.

Almost surely, 2^667557313920 is an apocalyptic number.

667557313920 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 667557313920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1426878097920).

667557313920 is an abundant number, since it is smaller than the sum of its proper divisors (2186198881920).

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

667557313920 is an equidigital number, since it uses as much as digits as its factorization.

667557313920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8954 (or 8927 counting only the distinct ones).

The product of its (nonzero) digits is 7144200, while the sum is 54.

The spelling of 667557313920 in words is "six hundred sixty-seven billion, five hundred fifty-seven million, three hundred thirteen thousand, nine hundred twenty".