666605509950 has 96 divisors (see below), whose sum is σ = 1672355462400. Its totient is φ = 175701208320.

The previous prime is 666605509939. The next prime is 666605509961. The reversal of 666605509950 is 59905506666.

It is an interprime number because it is at equal distance from previous prime (666605509939) and next prime (666605509961).

It is a Curzon number.

It is a congruent number.

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, 46223841 + ... + 46238259.

It is an arithmetic number, because the mean of its divisors is an integer number (17420369400).

Almost surely, 2^666605509950 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666605509950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (836177731200).

666605509950 is an abundant number, since it is smaller than the sum of its proper divisors (1005749952450).

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

666605509950 is a wasteful number, since it uses less digits than its factorization.

666605509950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17986 (or 17981 counting only the distinct ones).

The product of its (nonzero) digits is 13122000, while the sum is 57.

The spelling of 666605509950 in words is "six hundred sixty-six billion, six hundred five million, five hundred nine thousand, nine hundred fifty".