18961496281728 has 3456 divisors, whose sum is σ = 81953223992640. Its totient is φ = 4289067417600.

The previous prime is 18961496281727. The next prime is 18961496281789. The reversal of 18961496281728 is 82718269416981.

18961496281728 is a `hidden beast` number, since 1 + 8 + 9 + 61 + 496 + 2 + 8 + 1 + 72 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (3456).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18961496281727) by changing a digit.

It is a polite number, since it can be written in 431 ways as a sum of consecutive naturals, for example, 78678407688 + ... + 78678407928.

Almost surely, 2^{18961496281728} is an apocalyptic number.

18961496281728 is a gapful number since it is divisible by the number (18) 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 18961496281728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40976611996320).

18961496281728 is an abundant number, since it is smaller than the sum of its proper divisors (62991727710912).

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

18961496281728 is a wasteful number, since it uses less digits than its factorization.

18961496281728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 296 counting only the distinct ones).

The product of its digits is 167215104, while the sum is 72.

The spelling of 18961496281728 in words is "eighteen trillion, nine hundred sixty-one billion, four hundred ninety-six million, two hundred eighty-one thousand, seven hundred twenty-eight".