211021211021 has 16 divisors (see below), whose sum is σ = 225687413808. Its totient is φ = 196606080000.

The previous prime is 211021210991. The next prime is 211021211039. The reversal of 211021211021 is 120112120112.

It can be written as a sum of positive squares in 8 ways, for example, as 73186480900 + 137834730121 = 270530^2 + 371261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211021211021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211021210987 and 211021211005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211021211041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16993811 + ... + 17006223.

It is an arithmetic number, because the mean of its divisors is an integer number (14105463363).

Almost surely, 2^211021211021 is an apocalyptic number.

It is an amenable number.

211021211021 is a deficient number, since it is larger than the sum of its proper divisors (14666202787).

211021211021 is a wasteful number, since it uses less digits than its factorization.

211021211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22432.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 211021211021 its reverse (120112120112), we get a palindrome (331133331133).

Subtracting from 211021211021 its reverse (120112120112), we obtain a palindrome (90909090909).

The spelling of 211021211021 in words is "two hundred eleven billion, twenty-one million, two hundred eleven thousand, twenty-one".