6661639950 has 96 divisors (see below), whose sum is σ = 18902647296. Its totient is φ = 1520914560.

The previous prime is 6661639949. The next prime is 6661639961. The reversal of 6661639950 is 599361666.

It is a junction number, because it is equal to n+sod(n) for n = 6661639893 and 6661639902.

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, 1060519 + ... + 1066781.

It is an arithmetic number, because the mean of its divisors is an integer number (196902576).

Almost surely, 2^6661639950 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6661639950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9451323648).

6661639950 is an abundant number, since it is smaller than the sum of its proper divisors (12241007346).

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

6661639950 is a wasteful number, since it uses less digits than its factorization.

6661639950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7298 (or 7293 counting only the distinct ones).

The product of its (nonzero) digits is 1574640, while the sum is 51.

The square root of 6661639950 is about 81618.8700607893. The cubic root of 6661639950 is about 1881.5989066733.

The spelling of 6661639950 in words is "six billion, six hundred sixty-one million, six hundred thirty-nine thousand, nine hundred fifty".