667650440 has 64 divisors (see below), whose sum is σ = 1571529600. Its totient is φ = 254797312.

The previous prime is 667650421. The next prime is 667650449. The reversal of 667650440 is 44056766.

It is a super-2 number, since 2×667650440² = 891514220064387200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 667650394 and 667650403.

It is not an unprimeable number, because it can be changed into a prime (667650449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 517316 + ... + 518604.

It is an arithmetic number, because the mean of its divisors is an integer number (24555150).

Almost surely, 2^667650440 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 667650440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785764800).

667650440 is an abundant number, since it is smaller than the sum of its proper divisors (903879160).

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

667650440 is a wasteful number, since it uses less digits than its factorization.

667650440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1886 (or 1882 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 667650440 is about 25838.9326404943. The cubic root of 667650440 is about 874.0099561273.

The spelling of 667650440 in words is "six hundred sixty-seven million, six hundred fifty thousand, four hundred forty".