221000000000000 has 676 divisors, whose sum is σ = 629923095187092. Its totient is φ = 76800000000000.

The previous prime is 220999999999939. The next prime is 221000000000023. The reversal of 221000000000000 is 122.

It can be written as a sum of positive squares in 26 ways, for example, as 218161880252416 + 2838119747584 = 14770304^2 + 1684672^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 220999999999894 and 220999999999903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 51 ways as a sum of consecutive naturals, for example, 12999999999992 + ... + 13000000000008.

Almost surely, 2^{221000000000000} is an apocalyptic number.

221000000000000 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 221000000000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (314961547593546).

221000000000000 is an abundant number, since it is smaller than the sum of its proper divisors (408923095187092).

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

221000000000000 is an frugal number, since it uses more digits than its factorization.

221000000000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 37 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

Adding to 221000000000000 its reverse (122), we get a palindrome (221000000000122).

The spelling of 221000000000000 in words is "two hundred twenty-one trillion", and thus it is an aban number.