660402540 has 144 divisors (see below), whose sum is σ = 2307981312. Its totient is φ = 149724288.

The previous prime is 660402521. The next prime is 660402541. The reversal of 660402540 is 45204066.

It is a happy number.

660402540 is a `hidden beast` number, since 6 + 604 + 0 + 2 + 54 + 0 = 666.

It is a super-2 number, since 2×660402540² = 872263029676903200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (660402541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 157957 + ... + 162083.

It is an arithmetic number, because the mean of its divisors is an integer number (16027648).

Almost surely, 2^660402540 is an apocalyptic number.

660402540 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 660402540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1153990656).

660402540 is an abundant number, since it is smaller than the sum of its proper divisors (1647578772).

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

660402540 is a wasteful number, since it uses less digits than its factorization.

660402540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4276 (or 4271 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 660402540 is about 25698.2983872474. The cubic root of 660402540 is about 870.8357407095.

The spelling of 660402540 in words is "six hundred sixty million, four hundred two thousand, five hundred forty".