343521891221 has 2 divisors, whose sum is σ = 343521891222. Its totient is φ = 343521891220.

The previous prime is 343521891211. The next prime is 343521891263. The reversal of 343521891221 is 122198125343.

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., 267869388721 + 75652502500 = 517561^2 + 275050^2 .

It is a cyclic number.

It is not a de Polignac number, because 343521891221 - 2²² = 343517696917 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (343521891211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171760945610 + 171760945611.

It is an arithmetic number, because the mean of its divisors is an integer number (171760945611).

Almost surely, 2^343521891221 is an apocalyptic number.

It is an amenable number.

343521891221 is a deficient number, since it is larger than the sum of its proper divisors (1).

343521891221 is an equidigital number, since it uses as much as digits as its factorization.

343521891221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The spelling of 343521891221 in words is "three hundred forty-three billion, five hundred twenty-one million, eight hundred ninety-one thousand, two hundred twenty-one".