21600180900 has 405 divisors, whose sum is σ = 74241378673. Its totient is φ = 5432011200.

The previous prime is 21600180881. The next prime is 21600180991. The reversal of 21600180900 is 908100612.

The square root of 21600180900 is 146970.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7776065124 + 13824115776 = 88182^2 + 117576^2 .

It is a tau number, because it is divible by the number of its divisors (405).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 304227865 + ... + 304227935.

Almost surely, 2^21600180900 is an apocalyptic number.

21600180900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21600180900 is the 146970-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21600180900

21600180900 is an abundant number, since it is smaller than the sum of its proper divisors (52641197773).

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

21600180900 is a wasteful number, since it uses less digits than its factorization.

21600180900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

It can be divided in two parts, 21600 and 180900, that added together give a square (202500 = 450²).

The spelling of 21600180900 in words is "twenty-one billion, six hundred million, one hundred eighty thousand, nine hundred".