221021011020 has 48 divisors (see below), whose sum is σ = 628095541248. Its totient is φ = 58059249600.

The previous prime is 221021011019. The next prime is 221021011033. The reversal of 221021011020 is 20110120122.

It is a super-2 number, since 2×221021011020² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 221021010987 and 221021011005.

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, 27486156 + ... + 27494195.

It is an arithmetic number, because the mean of its divisors is an integer number (13085323776).

Almost surely, 2^221021011020 is an apocalyptic number.

221021011020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021011020 is an abundant number, since it is smaller than the sum of its proper divisors (407074530228).

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

221021011020 is a wasteful number, since it uses less digits than its factorization.

221021011020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54980430 (or 54980428 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 221021011020 its reverse (20110120122), we get a palindrome (241131131142).

The spelling of 221021011020 in words is "two hundred twenty-one billion, twenty-one million, eleven thousand, twenty".