666261740 has 12 divisors (see below), whose sum is σ = 1399149696. Its totient is φ = 266504688.

The previous prime is 666261727. The next prime is 666261749. The reversal of 666261740 is 47162666.

It is a junction number, because it is equal to n+sod(n) for n = 666261694 and 666261703.

It is not an unprimeable number, because it can be changed into a prime (666261749) 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 3 ways as a sum of consecutive naturals, for example, 16656524 + ... + 16656563.

It is an arithmetic number, because the mean of its divisors is an integer number (116595808).

Almost surely, 2^666261740 is an apocalyptic number.

It is an amenable number.

666261740 is an abundant number, since it is smaller than the sum of its proper divisors (732887956).

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

666261740 is a wasteful number, since it uses less digits than its factorization.

666261740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33313096 (or 33313094 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 666261740 is about 25812.0464124796. The cubic root of 666261740 is about 873.4035609021.

The spelling of 666261740 in words is "six hundred sixty-six million, two hundred sixty-one thousand, seven hundred forty".