212011021 has 4 divisors (see below), whose sum is σ = 212094652. Its totient is φ = 211927392.

The previous prime is 212010989. The next prime is 212011043. The reversal of 212011021 is 120110212.

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 107868996 + 104142025 = 10386^2 + 10205^2 .

It is a cyclic number.

It is not a de Polignac number, because 212011021 - 2⁵ = 212010989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212010989 and 212011007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212011421) 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, 37890 + ... + 43123.

It is an arithmetic number, because the mean of its divisors is an integer number (53023663).

Almost surely, 2^212011021 is an apocalyptic number.

It is an amenable number.

212011021 is a deficient number, since it is larger than the sum of its proper divisors (83631).

212011021 is an equidigital number, since it uses as much as digits as its factorization.

212011021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83630.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 212011021 is about 14560.5982363363. The cubic root of 212011021 is about 596.2835281848.

Adding to 212011021 its reverse (120110212), we get a palindrome (332121233).

It can be divided in two parts, 21201 and 1021, that added together give a palindrome (22222).

The spelling of 212011021 in words is "two hundred twelve million, eleven thousand, twenty-one".