1011211120021 has 4 divisors (see below), whose sum is σ = 1011213228844. Its totient is φ = 1011209011200.

The previous prime is 1011211119959. The next prime is 1011211120061. The reversal of 1011211120021 is 1200211121101.

It is a happy number.

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 647680505796 + 363530614225 = 804786^2 + 602935^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011211120021 - 2³³ = 1002621185429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1011211119983 and 1011211120010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011211120061) 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, 51511 + ... + 1423051.

It is an arithmetic number, because the mean of its divisors is an integer number (252803307211).

Almost surely, 2^{1011211120021} is an apocalyptic number.

It is an amenable number.

1011211120021 is a deficient number, since it is larger than the sum of its proper divisors (2108823).

1011211120021 is an equidigital number, since it uses as much as digits as its factorization.

1011211120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2108822.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1011211120021 its reverse (1200211121101), we get a palindrome (2211422241122).

The spelling of 1011211120021 in words is "one trillion, eleven billion, two hundred eleven million, one hundred twenty thousand, twenty-one".