211312021 has 4 divisors (see below), whose sum is σ = 211391532. Its totient is φ = 211232512.

The previous prime is 211311983. The next prime is 211312043. The reversal of 211312021 is 120213112.

211312021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 194909521 + 16402500 = 13961^2 + 4050^2 .

It is a cyclic number.

It is not a de Polignac number, because 211312021 - 2²⁵ = 177757589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211311992 and 211312010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211312721) 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, 35626 + ... + 41131.

It is an arithmetic number, because the mean of its divisors is an integer number (52847883).

Almost surely, 2^211312021 is an apocalyptic number.

It is an amenable number.

211312021 is a deficient number, since it is larger than the sum of its proper divisors (79511).

211312021 is an equidigital number, since it uses as much as digits as its factorization.

211312021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79510.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 211312021 is about 14536.5752844334. The cubic root of 211312021 is about 595.6274913893.

Adding to 211312021 its reverse (120213112), we get a palindrome (331525133).

The spelling of 211312021 in words is "two hundred eleven million, three hundred twelve thousand, twenty-one".