213400240021 has 2 divisors, whose sum is σ = 213400240022. Its totient is φ = 213400240020.

The previous prime is 213400240013. The next prime is 213400240057. The reversal of 213400240021 is 120042004312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130979571921 + 82420668100 = 361911^2 + 287090^2 .

It is a cyclic number.

It is not a de Polignac number, because 213400240021 - 2³ = 213400240013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213400240421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106700120010 + 106700120011.

It is an arithmetic number, because the mean of its divisors is an integer number (106700120011).

Almost surely, 2^213400240021 is an apocalyptic number.

It is an amenable number.

213400240021 is a deficient number, since it is larger than the sum of its proper divisors (1).

213400240021 is an equidigital number, since it uses as much as digits as its factorization.

213400240021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 213400240021 its reverse (120042004312), we get a palindrome (333442244333).

The spelling of 213400240021 in words is "two hundred thirteen billion, four hundred million, two hundred forty thousand, twenty-one".