221220400421424 has 80 divisors (see below), whose sum is σ = 605181472156800. Its totient is φ = 69393462113280.

The previous prime is 221220400421399. The next prime is 221220400421437. The reversal of 221220400421424 is 424124004022122.

It is a junction number, because it is equal to n+sod(n) for n = 221220400421391 and 221220400421400.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11324022 + ... + 23888789.

It is an arithmetic number, because the mean of its divisors is an integer number (7564768401960).

Almost surely, 2^{221220400421424} is an apocalyptic number.

221220400421424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221220400421424 is an abundant number, since it is smaller than the sum of its proper divisors (383961071735376).

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

221220400421424 is a wasteful number, since it uses less digits than its factorization.

221220400421424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35220538 (or 35220532 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 30.

Adding to 221220400421424 its reverse (424124004022122), we get a palindrome (645344404443546).

The spelling of 221220400421424 in words is "two hundred twenty-one trillion, two hundred twenty billion, four hundred million, four hundred twenty-one thousand, four hundred twenty-four".