21524240000 has 160 divisors (see below), whose sum is σ = 54080141940. Its totient is φ = 8529920000.

The previous prime is 21524239969. The next prime is 21524240011. The reversal of 21524240000 is 4242512.

It is a happy number.

It can be written as a sum of positive squares in 10 ways, for example, as 15007230016 + 6517009984 = 122504^2 + 80728^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9038810 + ... + 9041190.

Almost surely, 2^21524240000 is an apocalyptic number.

21524240000 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 21524240000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27040070970).

21524240000 is an abundant number, since it is smaller than the sum of its proper divisors (32555901940).

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

21524240000 is an equidigital number, since it uses as much as digits as its factorization.

21524240000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2528 (or 2501 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 21524240000 its reverse (4242512), we get a palindrome (21528482512).

The spelling of 21524240000 in words is "twenty-one billion, five hundred twenty-four million, two hundred forty thousand".