18213511680 has 1440 divisors, whose sum is σ = 84815915184. Its totient is φ = 3567255552.

The previous prime is 18213511649. The next prime is 18213511727. The reversal of 18213511680 is 8611531281.

18213511680 is a `hidden beast` number, since 1 + 82 + 1 + 3 + 511 + 68 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 7573176576 + 10640335104 = 87024^2 + 103152^2 .

It is a tau number, because it is divible by the number of its divisors (1440).

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 249500124 + ... + 249500196.

Almost surely, 2^18213511680 is an apocalyptic number.

18213511680 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 18213511680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42407957592).

18213511680 is an abundant number, since it is smaller than the sum of its proper divisors (66602403504).

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

18213511680 is a wasteful number, since it uses less digits than its factorization.

18213511680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The spelling of 18213511680 in words is "eighteen billion, two hundred thirteen million, five hundred eleven thousand, six hundred eighty".