21240264024 has 120 divisors (see below), whose sum is σ = 67109887260. Its totient is φ = 6068597472.

The previous prime is 21240264011. The next prime is 21240264029. The reversal of 21240264024 is 42046204212.

21240264024 is a `hidden beast` number, since 2 + 12 + 4 + 0 + 2 + 640 + 2 + 4 = 666.

It is a super-2 number, since 2×21240264024² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240264029) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 111439 + ... + 234305.

Almost surely, 2^21240264024 is an apocalyptic number.

21240264024 is a gapful number since it is divisible by the number (24) 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 21240264024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33554943630).

21240264024 is an abundant number, since it is smaller than the sum of its proper divisors (45869623236).

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

21240264024 is a wasteful number, since it uses less digits than its factorization.

21240264024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122907 (or 122879 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

Adding to 21240264024 its reverse (42046204212), we get a palindrome (63286468236).

The spelling of 21240264024 in words is "twenty-one billion, two hundred forty million, two hundred sixty-four thousand, twenty-four".