345021205421 has 2 divisors, whose sum is σ = 345021205422. Its totient is φ = 345021205420.

The previous prime is 345021205411. The next prime is 345021205513. The reversal of 345021205421 is 124502120543.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 174712296196 + 170308909225 = 417986^2 + 412685^2 .

It is an emirp because it is prime and its reverse (124502120543) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-345021205421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (345021205411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172510602710 + 172510602711.

It is an arithmetic number, because the mean of its divisors is an integer number (172510602711).

Almost surely, 2^345021205421 is an apocalyptic number.

It is an amenable number.

345021205421 is a deficient number, since it is larger than the sum of its proper divisors (1).

345021205421 is an equidigital number, since it uses as much as digits as its factorization.

345021205421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 345021205421 its reverse (124502120543), we get a palindrome (469523325964).

It can be divided in two parts, 34502120542 and 1, that added together give a palindrome (34502120543).

The spelling of 345021205421 in words is "three hundred forty-five billion, twenty-one million, two hundred five thousand, four hundred twenty-one".