21201200221220 has 48 divisors (see below), whose sum is σ = 46250808057216. Its totient is φ = 8157108960000.

The previous prime is 21201200221217. The next prime is 21201200221297. The reversal of 21201200221220 is 2212200210212.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182020106 + ... + 182136545.

It is an arithmetic number, because the mean of its divisors is an integer number (963558501192).

Almost surely, 2^{21201200221220} is an apocalyptic number.

21201200221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201200221220 is an abundant number, since it is smaller than the sum of its proper divisors (25049607835996).

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

21201200221220 is a wasteful number, since it uses less digits than its factorization.

21201200221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364156772 (or 364156770 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21201200221220 its reverse (2212200210212), we get a palindrome (23413400431432).

The spelling of 21201200221220 in words is "twenty-one trillion, two hundred one billion, two hundred million, two hundred twenty-one thousand, two hundred twenty".