21015240000 has 280 divisors, whose sum is σ = 70462444800. Its totient is φ = 5524992000.

The previous prime is 21015239969. The next prime is 21015240041. The reversal of 21015240000 is 4251012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8758801 + ... + 8761199.

Almost surely, 2^21015240000 is an apocalyptic number.

21015240000 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 21015240000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35231222400).

21015240000 is an abundant number, since it is smaller than the sum of its proper divisors (49447204800).

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

21015240000 is an equidigital number, since it uses as much as digits as its factorization.

21015240000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2507 (or 2482 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21015240000 its reverse (4251012), we get a palindrome (21019491012).

The spelling of 21015240000 in words is "twenty-one billion, fifteen million, two hundred forty thousand".