21123491760900 has 405 divisors, whose sum is σ = 69084122174991. Its totient is φ = 5583183707520.

The previous prime is 21123491760829. The next prime is 21123491760901. The reversal of 21123491760900 is 906719432112.

The square root of 21123491760900 is 4596030.

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

21123491760900 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 3 + 491 + 76 + 0 + 90 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2882939118084 + 18240552642816 = 1697922^2 + 4270896^2 .

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 (45).

It is not an unprimeable number, because it can be changed into a prime (21123491760901) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 92242321986 + ... + 92242322214.

Almost surely, 2^{21123491760900} is an apocalyptic number.

21123491760900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21123491760900 is the 4596030-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123491760900

21123491760900 is an abundant number, since it is smaller than the sum of its proper divisors (47960630414091).

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

21123491760900 is an equidigital number, since it uses as much as digits as its factorization.

21123491760900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 930 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The spelling of 21123491760900 in words is "twenty-one trillion, one hundred twenty-three billion, four hundred ninety-one million, seven hundred sixty thousand, nine hundred".