213400240421 has 2 divisors, whose sum is σ = 213400240422. Its totient is φ = 213400240420.

The previous prime is 213400240379. The next prime is 213400240499. The reversal of 213400240421 is 124042004312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107800588900 + 105599651521 = 328330^2 + 324961^2 .

It is a cyclic number.

It is not a de Polignac number, because 213400240421 - 2⁶ = 213400240357 is a prime.

It is a super-2 number, since 2×213400240421² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213400240021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106700120210 + 106700120211.

It is an arithmetic number, because the mean of its divisors is an integer number (106700120211).

Almost surely, 2^213400240421 is an apocalyptic number.

It is an amenable number.

213400240421 is a deficient number, since it is larger than the sum of its proper divisors (1).

213400240421 is an equidigital number, since it uses as much as digits as its factorization.

213400240421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 213400240421 its reverse (124042004312), we get a palindrome (337442244733).

The spelling of 213400240421 in words is "two hundred thirteen billion, four hundred million, two hundred forty thousand, four hundred twenty-one".