18815532120 has 640 divisors, whose sum is σ = 80390154240. Its totient is φ = 3833256960.

The previous prime is 18815532101. The next prime is 18815532121. The reversal of 18815532120 is 2123551881.

18815532120 is a `hidden beast` number, since 1 + 8 + 81 + 553 + 2 + 1 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18815532121) by changing a digit.

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 159 ways as a sum of consecutive naturals, for example, 13221729 + ... + 13223151.

It is an arithmetic number, because the mean of its divisors is an integer number (125609616).

Almost surely, 2^18815532120 is an apocalyptic number.

18815532120 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 18815532120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40195077120).

18815532120 is an abundant number, since it is smaller than the sum of its proper divisors (61574622120).

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

18815532120 is a wasteful number, since it uses less digits than its factorization.

18815532120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517 (or 1504 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The spelling of 18815532120 in words is "eighteen billion, eight hundred fifteen million, five hundred thirty-two thousand, one hundred twenty".