21040134912 has 180 divisors, whose sum is σ = 62883116296. Its totient is φ = 6997155840.

The previous prime is 21040134911. The next prime is 21040134917. The reversal of 21040134912 is 21943104012.

It is a happy number.

21040134912 is a `hidden beast` number, since 210 + 401 + 3 + 49 + 1 + 2 = 666.

It is a super-2 number, since 2×21040134912² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21040134911) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11839368 + ... + 11841144.

Almost surely, 2^21040134912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21040134912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31441558148).

21040134912 is an abundant number, since it is smaller than the sum of its proper divisors (41842981384).

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

21040134912 is an equidigital number, since it uses as much as digits as its factorization.

21040134912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2376 (or 2353 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

Adding to 21040134912 its reverse (21943104012), we get a palindrome (42983238924).

The spelling of 21040134912 in words is "twenty-one billion, forty million, one hundred thirty-four thousand, nine hundred twelve".