1020111021221 has 4 divisors (see below), whose sum is σ = 1030211130444. Its totient is φ = 1010010912000.

The previous prime is 1020111021199. The next prime is 1020111021239. The reversal of 1020111021221 is 1221201110201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 900384640996 + 119726380225 = 948886^2 + 346015^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020111021221 - 2¹⁴ = 1020111004837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020111021196 and 1020111021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020111021521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5050054460 + ... + 5050054661.

It is an arithmetic number, because the mean of its divisors is an integer number (257552782611).

Almost surely, 2^{1020111021221} is an apocalyptic number.

It is an amenable number.

1020111021221 is a deficient number, since it is larger than the sum of its proper divisors (10100109223).

1020111021221 is a wasteful number, since it uses less digits than its factorization.

1020111021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10100109222.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1020111021221 its reverse (1221201110201), we get a palindrome (2241312131422).

The spelling of 1020111021221 in words is "one trillion, twenty billion, one hundred eleven million, twenty-one thousand, two hundred twenty-one".