213432421 has 2 divisors, whose sum is σ = 213432422. Its totient is φ = 213432420.

The previous prime is 213432409. The next prime is 213432449. The reversal of 213432421 is 124234312.

213432421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155900196 + 57532225 = 12486^2 + 7585^2 .

It is a cyclic number.

It is not a de Polignac number, because 213432421 - 2¹⁵ = 213399653 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 213432392 and 213432401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213432451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106716210 + 106716211.

It is an arithmetic number, because the mean of its divisors is an integer number (106716211).

Almost surely, 2^213432421 is an apocalyptic number.

It is an amenable number.

213432421 is a deficient number, since it is larger than the sum of its proper divisors (1).

213432421 is an equidigital number, since it uses as much as digits as its factorization.

213432421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 22.

The square root of 213432421 is about 14609.3265074062. The cubic root of 213432421 is about 597.6131293758.

Adding to 213432421 its reverse (124234312), we get a palindrome (337666733).

The spelling of 213432421 in words is "two hundred thirteen million, four hundred thirty-two thousand, four hundred twenty-one".