212433021 has 12 divisors (see below), whose sum is σ = 315141372. Its totient is φ = 137794176.

The previous prime is 212433017. The next prime is 212433031. The reversal of 212433021 is 120334212.

212433021 is a `hidden beast` number, since 212 + 433 + 0 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 125216100 + 87216921 = 11190^2 + 9339^2 .

It is not a de Polignac number, because 212433021 - 2² = 212433017 is a prime.

It is a super-2 number, since 2×212433021² = 90255576822372882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 212432985 and 212433003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212433031) 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, 318636 + ... + 319301.

It is an arithmetic number, because the mean of its divisors is an integer number (26261781).

Almost surely, 2^212433021 is an apocalyptic number.

It is an amenable number.

212433021 is a deficient number, since it is larger than the sum of its proper divisors (102708351).

212433021 is a wasteful number, since it uses less digits than its factorization.

212433021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637980 (or 637977 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 212433021 is about 14575.0821953085. The cubic root of 212433021 is about 596.6788926610.

Adding to 212433021 its reverse (120334212), we get a palindrome (332767233).

The spelling of 212433021 in words is "two hundred twelve million, four hundred thirty-three thousand, twenty-one".