667729920 has 480 divisors, whose sum is σ = 2642330880. Its totient is φ = 141557760.

The previous prime is 667729919. The next prime is 667730023. The reversal of 667729920 is 29927766.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 667729920.

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, 35143671 + ... + 35143689.

It is an arithmetic number, because the mean of its divisors is an integer number (5504856).

Almost surely, 2^667729920 is an apocalyptic number.

667729920 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 667729920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1321165440).

667729920 is an abundant number, since it is smaller than the sum of its proper divisors (1974600960).

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

667729920 is a wasteful number, since it uses less digits than its factorization.

667729920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 48.

The square root of 667729920 is about 25840.4705839503. The cubic root of 667729920 is about 874.0446367280.

The spelling of 667729920 in words is "six hundred sixty-seven million, seven hundred twenty-nine thousand, nine hundred twenty".