16661251163440 has 160 divisors (see below), whose sum is σ = 41909957591040. Its totient is φ = 6123461250048.

The previous prime is 16661251163407. The next prime is 16661251163521. The reversal of 16661251163440 is 4436115216661.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 344337489 + ... + 344385871.

It is an arithmetic number, because the mean of its divisors is an integer number (261937234944).

Almost surely, 2^{16661251163440} is an apocalyptic number.

16661251163440 is a gapful number since it is divisible by the number (10) 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 16661251163440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20954978795520).

16661251163440 is an abundant number, since it is smaller than the sum of its proper divisors (25248706427600).

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

16661251163440 is a wasteful number, since it uses less digits than its factorization.

16661251163440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49931 (or 49925 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 16661251163440 in words is "sixteen trillion, six hundred sixty-one billion, two hundred fifty-one million, one hundred sixty-three thousand, four hundred forty".