665143920 has 160 divisors (see below), whose sum is σ = 2618403840. Its totient is φ = 152029440.

The previous prime is 665143901. The next prime is 665143933. The reversal of 665143920 is 29341566.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 6876 + ... + 37115.

It is an arithmetic number, because the mean of its divisors is an integer number (16365024).

Almost surely, 2^665143920 is an apocalyptic number.

665143920 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 665143920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1309201920).

665143920 is an abundant number, since it is smaller than the sum of its proper divisors (1953259920).

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

665143920 is a wasteful number, since it uses less digits than its factorization.

665143920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44020 (or 44008 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 665143920 is about 25790.3842546016. The cubic root of 665143920 is about 872.9148368170.

The spelling of 665143920 in words is "six hundred sixty-five million, one hundred forty-three thousand, nine hundred twenty".