12563601666 has 96 divisors (see below), whose sum is σ = 32185734912. Its totient is φ = 3232686240.

The previous prime is 12563601643. The next prime is 12563601689. The reversal of 12563601666 is 66610636521.

It is an interprime number because it is at equal distance from previous prime (12563601643) and next prime (12563601689).

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 327885 + ... + 364191.

It is an arithmetic number, because the mean of its divisors is an integer number (335268072).

Almost surely, 2^12563601666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12563601666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16092867456).

12563601666 is an abundant number, since it is smaller than the sum of its proper divisors (19622133246).

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

12563601666 is a wasteful number, since it uses less digits than its factorization.

12563601666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36444 (or 36437 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 42.

The spelling of 12563601666 in words is "twelve billion, five hundred sixty-three million, six hundred one thousand, six hundred sixty-six".