18201971994624 has 416 divisors, whose sum is σ = 59277058663680. Its totient is φ = 5473596211200.

The previous prime is 18201971994559. The next prime is 18201971994683. The reversal of 18201971994624 is 42649917910281.

18201971994624 is a `hidden beast` number, since 1 + 8 + 2 + 0 + 19 + 71 + 99 + 462 + 4 = 666.

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, 159305964 + ... + 159420180.

It is an arithmetic number, because the mean of its divisors is an integer number (142492929480).

Almost surely, 2^{18201971994624} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18201971994624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29638529331840).

18201971994624 is an abundant number, since it is smaller than the sum of its proper divisors (41075086669056).

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

18201971994624 is a wasteful number, since it uses less digits than its factorization.

18201971994624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114392 (or 114364 counting only the distinct ones).

The product of its (nonzero) digits is 15676416, while the sum is 63.

The spelling of 18201971994624 in words is "eighteen trillion, two hundred one billion, nine hundred seventy-one million, nine hundred ninety-four thousand, six hundred twenty-four".