18993910428 has 96 divisors (see below), whose sum is σ = 52072151040. Its totient is φ = 5977584000.

The previous prime is 18993910417. The next prime is 18993910477. The reversal of 18993910428 is 82401939981.

18993910428 is a `hidden beast` number, since 189 + 9 + 39 + 1 + 0 + 428 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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, 68083 + ... + 206453.

It is an arithmetic number, because the mean of its divisors is an integer number (542418240).

Almost surely, 2^18993910428 is an apocalyptic number.

18993910428 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 18993910428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26036075520).

18993910428 is an abundant number, since it is smaller than the sum of its proper divisors (33078240612).

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

18993910428 is a wasteful number, since it uses less digits than its factorization.

18993910428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138456 (or 138448 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 18993910428 in words is "eighteen billion, nine hundred ninety-three million, nine hundred ten thousand, four hundred twenty-eight".