667643800 has 96 divisors (see below), whose sum is σ = 1643756400. Its totient is φ = 251758080.

The previous prime is 667643797. The next prime is 667643803. The reversal of 667643800 is 8346766.

It is an interprime number because it is at equal distance from previous prime (667643797) and next prime (667643803).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667643803) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 248062 + ... + 250738.

Almost surely, 2^667643800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667643800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (821878200).

667643800 is an abundant number, since it is smaller than the sum of its proper divisors (976112600).

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

667643800 is a wasteful number, since it uses less digits than its factorization.

667643800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2765 (or 2756 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 667643800 is about 25838.8041518953. The cubic root of 667643800 is about 874.0070586803.

The spelling of 667643800 in words is "six hundred sixty-seven million, six hundred forty-three thousand, eight hundred".