667681560 has 384 divisors, whose sum is σ = 2712528000. Its totient is φ = 138682368.

The previous prime is 667681549. The next prime is 667681591. The reversal of 667681560 is 65186766.

667681560 is a `hidden beast` number, since 6 + 6 + 7 + 6 + 81 + 560 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2915526 + ... + 2915754.

It is an arithmetic number, because the mean of its divisors is an integer number (7063875).

Almost surely, 2^667681560 is an apocalyptic number.

667681560 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 667681560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1356264000).

667681560 is an abundant number, since it is smaller than the sum of its proper divisors (2044846440).

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

667681560 is a wasteful number, since it uses less digits than its factorization.

667681560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 667681560 is about 25839.5348255343. The cubic root of 667681560 is about 874.0235354724.

The spelling of 667681560 in words is "six hundred sixty-seven million, six hundred eighty-one thousand, five hundred sixty".