1021022212221 has 18 divisors (see below), whose sum is σ = 1621071998910. Its totient is φ = 618801340080.

The previous prime is 1021022212219. The next prime is 1021022212229. The reversal of 1021022212221 is 1222122201201.

It is a happy number.

1021022212221 is a `hidden beast` number, since 1 + 0 + 210 + 22 + 212 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 552139649721 + 468882562500 = 743061^2 + 684750^2 .

It is not a de Polignac number, because 1021022212221 - 2¹ = 1021022212219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021022212194 and 1021022212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021022212229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 468787806 + ... + 468789983.

It is an arithmetic number, because the mean of its divisors is an integer number (90059555495).

Almost surely, 2^{1021022212221} is an apocalyptic number.

1021022212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1021022212221 is a deficient number, since it is larger than the sum of its proper divisors (600049786689).

1021022212221 is a wasteful number, since it uses less digits than its factorization.

1021022212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 937577817 (or 937577803 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1021022212221 its reverse (1222122201201), we get a palindrome (2243144413422).

The spelling of 1021022212221 in words is "one trillion, twenty-one billion, twenty-two million, two hundred twelve thousand, two hundred twenty-one".