213321421 has 2 divisors, whose sum is σ = 213321422. Its totient is φ = 213321420.

The previous prime is 213321413. The next prime is 213321461. The reversal of 213321421 is 124123312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212751396 + 570025 = 14586^2 + 755^2 .

It is a cyclic number.

It is not a de Polignac number, because 213321421 - 2³ = 213321413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213321461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106660710 + 106660711.

It is an arithmetic number, because the mean of its divisors is an integer number (106660711).

Almost surely, 2^213321421 is an apocalyptic number.

It is an amenable number.

213321421 is a deficient number, since it is larger than the sum of its proper divisors (1).

213321421 is an equidigital number, since it uses as much as digits as its factorization.

213321421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 19.

The square root of 213321421 is about 14605.5270702567. The cubic root of 213321421 is about 597.5095110033.

Adding to 213321421 its reverse (124123312), we get a palindrome (337444733).

The spelling of 213321421 in words is "two hundred thirteen million, three hundred twenty-one thousand, four hundred twenty-one".