243234220421 has 2 divisors, whose sum is σ = 243234220422. Its totient is φ = 243234220420.

The previous prime is 243234220409. The next prime is 243234220429. The reversal of 243234220421 is 124022432342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182760525025 + 60473695396 = 427505^2 + 245914^2 .

It is a cyclic number.

It is not a de Polignac number, because 243234220421 - 2⁶ = 243234220357 is a prime.

It is a super-2 number, since 2×243234220421² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243234220429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121617110210 + 121617110211.

It is an arithmetic number, because the mean of its divisors is an integer number (121617110211).

Almost surely, 2^243234220421 is an apocalyptic number.

It is an amenable number.

243234220421 is a deficient number, since it is larger than the sum of its proper divisors (1).

243234220421 is an equidigital number, since it uses as much as digits as its factorization.

243234220421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18432, while the sum is 29.

Adding to 243234220421 its reverse (124022432342), we get a palindrome (367256652763).

The spelling of 243234220421 in words is "two hundred forty-three billion, two hundred thirty-four million, two hundred twenty thousand, four hundred twenty-one".