665569380 has 288 divisors, whose sum is σ = 2354220288. Its totient is φ = 137134080.

The previous prime is 665569379. The next prime is 665569409. The reversal of 665569380 is 83965566.

665569380 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6861492 + ... + 6861588.

It is an arithmetic number, because the mean of its divisors is an integer number (8174376).

Almost surely, 2^665569380 is an apocalyptic number.

665569380 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 665569380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1177110144).

665569380 is an abundant number, since it is smaller than the sum of its proper divisors (1688650908).

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

665569380 is a wasteful number, since it uses less digits than its factorization.

665569380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 48.

The square root of 665569380 is about 25798.6313590469. The cubic root of 665569380 is about 873.1009174415.

The spelling of 665569380 in words is "six hundred sixty-five million, five hundred sixty-nine thousand, three hundred eighty".