21500241136640 has 264 divisors, whose sum is σ = 60110935512912. Its totient is φ = 7357371678720.

The previous prime is 21500241136589. The next prime is 21500241136711. The reversal of 21500241136640 is 4663114200512.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 21500241136640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 131128310 + ... + 131292170.

Almost surely, 2^{21500241136640} is an apocalyptic number.

21500241136640 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 21500241136640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30055467756456).

21500241136640 is an abundant number, since it is smaller than the sum of its proper divisors (38610694376272).

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

21500241136640 is a wasteful number, since it uses less digits than its factorization.

21500241136640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164423 (or 164398 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 35.

The spelling of 21500241136640 in words is "twenty-one trillion, five hundred billion, two hundred forty-one million, one hundred thirty-six thousand, six hundred forty".