665516040 has 512 divisors, whose sum is σ = 2626560000. Its totient is φ = 134120448.

The previous prime is 665516023. The next prime is 665516113. The reversal of 665516040 is 40615566.

It is a junction number, because it is equal to n+sod(n) for n = 665515992 and 665516010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 17986902 + ... + 17986938.

It is an arithmetic number, because the mean of its divisors is an integer number (5130000).

Almost surely, 2^665516040 is an apocalyptic number.

665516040 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 665516040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1313280000).

665516040 is an abundant number, since it is smaller than the sum of its proper divisors (1961043960).

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

665516040 is a wasteful number, since it uses less digits than its factorization.

665516040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 665516040 is about 25797.5975625638. The cubic root of 665516040 is about 873.0775928272.

The spelling of 665516040 in words is "six hundred sixty-five million, five hundred sixteen thousand, forty".