21500200055000 has 160 divisors (see below), whose sum is σ = 51611319840960. Its totient is φ = 8390179200000.

The previous prime is 21500200054987. The next prime is 21500200055011. The reversal of 21500200055000 is 55000200512.

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

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, 73408850 + ... + 73701150.

It is an arithmetic number, because the mean of its divisors is an integer number (322570749006).

Almost surely, 2^{21500200055000} is an apocalyptic number.

21500200055000 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 21500200055000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25805659920480).

21500200055000 is an abundant number, since it is smaller than the sum of its proper divisors (30111119785960).

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

21500200055000 is a wasteful number, since it uses less digits than its factorization.

21500200055000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292687 (or 292668 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 20.

Adding to 21500200055000 its reverse (55000200512), we get a palindrome (21555200255512).

The spelling of 21500200055000 in words is "twenty-one trillion, five hundred billion, two hundred million, fifty-five thousand".