667181438520 has 128 divisors (see below), whose sum is σ = 2026698408000. Its totient is φ = 175687335936.

The previous prime is 667181438519. The next prime is 667181438531. The reversal of 667181438520 is 25834181766.

It is a congruent number.

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, 5162532 + ... + 5290188.

Almost surely, 2^667181438520 is an apocalyptic number.

667181438520 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 667181438520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013349204000).

667181438520 is an abundant number, since it is smaller than the sum of its proper divisors (1359516969480).

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

667181438520 is a wasteful number, since it uses less digits than its factorization.

667181438520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128217 (or 128213 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 51.

The spelling of 667181438520 in words is "six hundred sixty-seven billion, one hundred eighty-one million, four hundred thirty-eight thousand, five hundred twenty".