665196840 has 512 divisors, whose sum is σ = 2916864000. Its totient is φ = 130636800.

The previous prime is 665196817. The next prime is 665196881. The reversal of 665196840 is 48691566.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1579830 + ... + 1580250.

It is an arithmetic number, because the mean of its divisors is an integer number (5697000).

Almost surely, 2^665196840 is an apocalyptic number.

665196840 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 665196840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1458432000).

665196840 is an abundant number, since it is smaller than the sum of its proper divisors (2251667160).

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

665196840 is a wasteful number, since it uses less digits than its factorization.

665196840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 665196840 is about 25791.4101979710. The cubic root of 665196840 is about 872.9379864075.

The spelling of 665196840 in words is "six hundred sixty-five million, one hundred ninety-six thousand, eight hundred forty".