212001021 has 12 divisors (see below), whose sum is σ = 306701148. Its totient is φ = 141113664.

The previous prime is 212001019. The next prime is 212001059. The reversal of 212001021 is 120100212.

It can be written as a sum of positive squares in 2 ways, for example, as 128936025 + 83064996 = 11355^2 + 9114^2 .

It is not a de Polignac number, because 212001021 - 2¹ = 212001019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 212000994 and 212001012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212001001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12160 + ... + 23913.

It is an arithmetic number, because the mean of its divisors is an integer number (25558429).

Almost surely, 2^212001021 is an apocalyptic number.

It is an amenable number.

212001021 is a deficient number, since it is larger than the sum of its proper divisors (94700127).

212001021 is a wasteful number, since it uses less digits than its factorization.

212001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36732 (or 36729 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 212001021 is about 14560.2548398028. The cubic root of 212001021 is about 596.2741529976.

Adding to 212001021 its reverse (120100212), we get a palindrome (332101233).

The spelling of 212001021 in words is "two hundred twelve million, one thousand, twenty-one".