18729494784 has 576 divisors, whose sum is σ = 74392442880. Its totient is φ = 4488929280.

The previous prime is 18729494761. The next prime is 18729494789. The reversal of 18729494784 is 48749492781.

18729494784 is a `hidden beast` number, since 1 + 8 + 72 + 9 + 494 + 78 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (63).

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

It is not an unprimeable number, because it can be changed into a prime (18729494789) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6917559 + ... + 6920265.

Almost surely, 2^18729494784 is an apocalyptic number.

18729494784 is a gapful number since it is divisible by the number (14) 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 18729494784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37196221440).

18729494784 is an abundant number, since it is smaller than the sum of its proper divisors (55662948096).

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

18729494784 is a wasteful number, since it uses less digits than its factorization.

18729494784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2763 (or 2743 counting only the distinct ones).

The product of its digits is 32514048, while the sum is 63.

The spelling of 18729494784 in words is "eighteen billion, seven hundred twenty-nine million, four hundred ninety-four thousand, seven hundred eighty-four".