21345120000 has 720 divisors, whose sum is σ = 81159145760. Its totient is φ = 5598720000.

The previous prime is 21345119987. The next prime is 21345120023. The reversal of 21345120000 is 2154312.

21345120000 is a `hidden beast` number, since 2 + 13 + 451 + 200 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-2 number, since 2×21345120000² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 349919970 + ... + 349920030.

Almost surely, 2^21345120000 is an apocalyptic number.

21345120000 is a gapful number since it is divisible by the number (20) 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 21345120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40579572880).

21345120000 is an abundant number, since it is smaller than the sum of its proper divisors (59814025760).

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

21345120000 is an frugal number, since it uses more digits than its factorization.

21345120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

Adding to 21345120000 its reverse (2154312), we get a palindrome (21347274312).

The spelling of 21345120000 in words is "twenty-one billion, three hundred forty-five million, one hundred twenty thousand".