340206405421 has 2 divisors, whose sum is σ = 340206405422. Its totient is φ = 340206405420.

The previous prime is 340206405403. The next prime is 340206405433. The reversal of 340206405421 is 124504602043.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 311598404100 + 28608001321 = 558210^2 + 169139^2 .

It is an emirp because it is prime and its reverse (124504602043) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 340206405421 - 2¹³ = 340206397229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (340206405221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170103202710 + 170103202711.

It is an arithmetic number, because the mean of its divisors is an integer number (170103202711).

Almost surely, 2^340206405421 is an apocalyptic number.

It is an amenable number.

340206405421 is a deficient number, since it is larger than the sum of its proper divisors (1).

340206405421 is an equidigital number, since it uses as much as digits as its factorization.

340206405421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 31.

The spelling of 340206405421 in words is "three hundred forty billion, two hundred six million, four hundred five thousand, four hundred twenty-one".