221521200000 has 384 divisors, whose sum is σ = 738942704640. Its totient is φ = 58794240000.

The previous prime is 221521199993. The next prime is 221521200077. The reversal of 221521200000 is 2125122.

It is a tau number, because it is divible by the number of its divisors (384).

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 47 ways as a sum of consecutive naturals, for example, 440399749 + ... + 440400251.

It is an arithmetic number, because the mean of its divisors is an integer number (1924329960).

Almost surely, 2^221521200000 is an apocalyptic number.

221521200000 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 221521200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369471352320).

221521200000 is an abundant number, since it is smaller than the sum of its proper divisors (517421504640).

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

221521200000 is an frugal number, since it uses more digits than its factorization.

221521200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912 (or 880 counting only the distinct ones).

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

Adding to 221521200000 its reverse (2125122), we get a palindrome (221523325122).

The spelling of 221521200000 in words is "two hundred twenty-one billion, five hundred twenty-one million, two hundred thousand".