1021211111021 has 4 divisors (see below), whose sum is σ = 1022473424700. Its totient is φ = 1019948797344.

The previous prime is 1021211110979. The next prime is 1021211111023. The reversal of 1021211111021 is 1201111121201.

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 512469856900 + 508741254121 = 715870^2 + 713261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021211111021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021211110987 and 1021211111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021211111023) 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, 631155626 + ... + 631157243.

It is an arithmetic number, because the mean of its divisors is an integer number (255618356175).

Almost surely, 2^{1021211111021} is an apocalyptic number.

It is an amenable number.

1021211111021 is a deficient number, since it is larger than the sum of its proper divisors (1262313679).

1021211111021 is an equidigital number, since it uses as much as digits as its factorization.

1021211111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262313678.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 1021211111021 its reverse (1201111121201), we get a palindrome (2222322232222).

The spelling of 1021211111021 in words is "one trillion, twenty-one billion, two hundred eleven million, one hundred eleven thousand, twenty-one".