18661852440 has 1280 divisors, whose sum is σ = 85642444800. Its totient is φ = 3527193600.

The previous prime is 18661852343. The next prime is 18661852457. The reversal of 18661852440 is 4425816681.

It is a happy number.

18661852440 is a `hidden beast` number, since 1 + 8 + 6 + 618 + 5 + 24 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 146943657 + ... + 146943783.

It is an arithmetic number, because the mean of its divisors is an integer number (66908160).

Almost surely, 2^18661852440 is an apocalyptic number.

18661852440 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 18661852440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42821222400).

18661852440 is an abundant number, since it is smaller than the sum of its proper divisors (66980592360).

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

18661852440 is a wasteful number, since it uses less digits than its factorization.

18661852440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 18661852440 in words is "eighteen billion, six hundred sixty-one million, eight hundred fifty-two thousand, four hundred forty".