11211110021 has 4 divisors (see below), whose sum is σ = 11212398444. Its totient is φ = 11209821600.

The previous prime is 11211110011. The next prime is 11211110023. The reversal of 11211110021 is 12001111211.

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 3534897025 + 7676212996 = 59455^2 + 87614^2 .

It is a cyclic number.

It is not a de Polignac number, because 11211110021 - 2¹⁸ = 11210847877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11211109984 and 11211110011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211110023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 631070 + ... + 648591.

It is an arithmetic number, because the mean of its divisors is an integer number (2803099611).

Almost surely, 2^11211110021 is an apocalyptic number.

It is an amenable number.

11211110021 is a deficient number, since it is larger than the sum of its proper divisors (1288423).

11211110021 is an equidigital number, since it uses as much as digits as its factorization.

11211110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288422.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 11211110021 its reverse (12001111211), we get a palindrome (23212221232).

The spelling of 11211110021 in words is "eleven billion, two hundred eleven million, one hundred ten thousand, twenty-one".