665428140 has 144 divisors (see below), whose sum is σ = 2186184000. Its totient is φ = 162860544.

The previous prime is 665428123. The next prime is 665428151. The reversal of 665428140 is 41824566.

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

It is a junction number, because it is equal to n+sod(n) for n = 665428095 and 665428104.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 464946 + ... + 466374.

Almost surely, 2^665428140 is an apocalyptic number.

665428140 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 665428140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093092000).

665428140 is an abundant number, since it is smaller than the sum of its proper divisors (1520755860).

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

665428140 is a wasteful number, since it uses less digits than its factorization.

665428140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1656 (or 1651 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 665428140 is about 25795.8938592947. The cubic root of 665428140 is about 873.0391530328.

The spelling of 665428140 in words is "six hundred sixty-five million, four hundred twenty-eight thousand, one hundred forty".