1021111111021 has 4 divisors (see below), whose sum is σ = 1031024811232. Its totient is φ = 1011197410812.

The previous prime is 1021111111001. The next prime is 1021111111099. The reversal of 1021111111021 is 1201111111201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1021111111021 - 2²³ = 1021102722413 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021111110992 and 1021111111010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021111111001) 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, 4956849951 + ... + 4956850156.

It is an arithmetic number, because the mean of its divisors is an integer number (257756202808).

Almost surely, 2^{1021111111021} is an apocalyptic number.

It is an amenable number.

1021111111021 is a deficient number, since it is larger than the sum of its proper divisors (9913700211).

1021111111021 is an equidigital number, since it uses as much as digits as its factorization.

1021111111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9913700210.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 1021111111021 its reverse (1201111111201), we get a palindrome (2222222222222).

The spelling of 1021111111021 in words is "one trillion, twenty-one billion, one hundred eleven million, one hundred eleven thousand, twenty-one".