667723680 has 288 divisors, whose sum is σ = 2503899216. Its totient is φ = 161021952.

The previous prime is 667723643. The next prime is 667723699. The reversal of 667723680 is 86327766.

667723680 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 179667216 + 488056464 = 13404^2 + 22092^2 .

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 991824 + ... + 992496.

Almost surely, 2^667723680 is an apocalyptic number.

667723680 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 667723680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1251949608).

667723680 is an abundant number, since it is smaller than the sum of its proper divisors (1836175536).

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

667723680 is a wasteful number, since it uses less digits than its factorization.

667723680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The square root of 667723680 is about 25840.3498428330. The cubic root of 667723680 is about 874.0419140426.

The spelling of 667723680 in words is "six hundred sixty-seven million, seven hundred twenty-three thousand, six hundred eighty".