221221120020 has 48 divisors (see below), whose sum is σ = 655855558848. Its totient is φ = 55522163200.

The previous prime is 221221119983. The next prime is 221221120069. The reversal of 221221120020 is 20021122122.

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 15 ways as a sum of consecutive naturals, for example, 108440706 + ... + 108442745.

It is an arithmetic number, because the mean of its divisors is an integer number (13663657476).

Almost surely, 2^221221120020 is an apocalyptic number.

221221120020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221120020 is an abundant number, since it is smaller than the sum of its proper divisors (434634438828).

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

221221120020 is a wasteful number, since it uses less digits than its factorization.

221221120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216883480 (or 216883478 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221221120020 its reverse (20021122122), we get a palindrome (241242242142).

The spelling of 221221120020 in words is "two hundred twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, twenty".