343621021 has 2 divisors, whose sum is σ = 343621022. Its totient is φ = 343621020.

The previous prime is 343621009. The next prime is 343621063. The reversal of 343621021 is 120126343.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 339664900 + 3956121 = 18430^2 + 1989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-343621021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 343620983 and 343621001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (343621121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171810510 + 171810511.

It is an arithmetic number, because the mean of its divisors is an integer number (171810511).

Almost surely, 2^343621021 is an apocalyptic number.

It is an amenable number.

343621021 is a deficient number, since it is larger than the sum of its proper divisors (1).

343621021 is an equidigital number, since it uses as much as digits as its factorization.

343621021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 343621021 is about 18537.0175864404. The cubic root of 343621021 is about 700.4222085569.

Adding to 343621021 its reverse (120126343), we get a palindrome (463747364).

The spelling of 343621021 in words is "three hundred forty-three million, six hundred twenty-one thousand, twenty-one".