18611987940 has 576 divisors, whose sum is σ = 74497812480. Its totient is φ = 3649536000.

The previous prime is 18611987903. The next prime is 18611987951. The reversal of 18611987940 is 4978911681.

18611987940 is a `hidden beast` number, since 18 + 611 + 9 + 8 + 7 + 9 + 4 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 24782565 + ... + 24783315.

It is an arithmetic number, because the mean of its divisors is an integer number (129336480).

Almost surely, 2^18611987940 is an apocalyptic number.

18611987940 is a gapful number since it is divisible by the number (10) 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 18611987940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37248906240).

18611987940 is an abundant number, since it is smaller than the sum of its proper divisors (55885824540).

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

18611987940 is a wasteful number, since it uses less digits than its factorization.

18611987940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 892 (or 887 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 54.

The spelling of 18611987940 in words is "eighteen billion, six hundred eleven million, nine hundred eighty-seven thousand, nine hundred forty".