221021011220 has 24 divisors (see below), whose sum is σ = 480149094600. Its totient is φ = 85359838592.

The previous prime is 221021011213. The next prime is 221021011331. The reversal of 221021011220 is 22110120122.

It can be written as a sum of positive squares in 4 ways, for example, as 81131546896 + 139889464324 = 284836^2 + 374018^2 .

It is a super-2 number, since 2×221021011220² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221021011195 and 221021011204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190534775 + ... + 190535934.

It is an arithmetic number, because the mean of its divisors is an integer number (20006212275).

Almost surely, 2^221021011220 is an apocalyptic number.

221021011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221021011220 is an abundant number, since it is smaller than the sum of its proper divisors (259128083380).

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

221021011220 is a wasteful number, since it uses less digits than its factorization.

221021011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381070747 (or 381070745 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221021011220 its reverse (22110120122), we get a palindrome (243131131342).

The spelling of 221021011220 in words is "two hundred twenty-one billion, twenty-one million, eleven thousand, two hundred twenty".