667397520 has 120 divisors (see below), whose sum is σ = 2262551616. Its totient is φ = 176289024.

The previous prime is 667397491. The next prime is 667397531. The reversal of 667397520 is 25793766.

It is a tau number, because it is divible by the number of its divisors (120).

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 23 ways as a sum of consecutive naturals, for example, 72709 + ... + 81371.

Almost surely, 2^667397520 is an apocalyptic number.

667397520 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 667397520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1131275808).

667397520 is an abundant number, since it is smaller than the sum of its proper divisors (1595154096).

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

667397520 is a wasteful number, since it uses less digits than its factorization.

667397520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8789 (or 8780 counting only the distinct ones).

The product of its (nonzero) digits is 476280, while the sum is 45.

The square root of 667397520 is about 25834.0380118943. The cubic root of 667397520 is about 873.8995777496.

The spelling of 667397520 in words is "six hundred sixty-seven million, three hundred ninety-seven thousand, five hundred twenty".