211111010021 has 8 divisors (see below), whose sum is σ = 212032543320. Its totient is φ = 210189609472.

The previous prime is 211111009931. The next prime is 211111010027. The reversal of 211111010021 is 120010111112.

It can be written as a sum of positive squares in 4 ways, for example, as 159112996 + 210951897025 = 12614^2 + 459295^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211111010021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211111009984 and 211111010011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211111010027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4490525 + ... + 4537293.

It is an arithmetic number, because the mean of its divisors is an integer number (26504067915).

Almost surely, 2^211111010021 is an apocalyptic number.

It is an amenable number.

211111010021 is a deficient number, since it is larger than the sum of its proper divisors (921533299).

211111010021 is a wasteful number, since it uses less digits than its factorization.

211111010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66375.

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

Adding to 211111010021 its reverse (120010111112), we get a palindrome (331121121133).

The spelling of 211111010021 in words is "two hundred eleven billion, one hundred eleven million, ten thousand, twenty-one".