211142021 has 4 divisors (see below), whose sum is σ = 211532844. Its totient is φ = 210751200.

The previous prime is 211141999. The next prime is 211142033. The reversal of 211142021 is 120241112.

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 38613796 + 172528225 = 6214^2 + 13135^2 .

It is a cyclic number.

It is not a de Polignac number, because 211142021 - 2¹⁰ = 211140997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 211141987 and 211142005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211142081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194600 + ... + 195681.

It is an arithmetic number, because the mean of its divisors is an integer number (52883211).

Almost surely, 2^211142021 is an apocalyptic number.

It is an amenable number.

211142021 is a deficient number, since it is larger than the sum of its proper divisors (390823).

211142021 is an equidigital number, since it uses as much as digits as its factorization.

211142021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390822.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 211142021 is about 14530.7267884301. The cubic root of 211142021 is about 595.4677215873.

Adding to 211142021 its reverse (120241112), we get a palindrome (331383133).

Subtracting from 211142021 its reverse (120241112), we obtain a palindrome (90900909).

The spelling of 211142021 in words is "two hundred eleven million, one hundred forty-two thousand, twenty-one".