13434643421 has 2 divisors, whose sum is σ = 13434643422. Its totient is φ = 13434643420.

The previous prime is 13434643399. The next prime is 13434643447. The reversal of 13434643421 is 12434643431.

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., 12273537796 + 1161105625 = 110786^2 + 34075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13434643421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13434643121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6717321710 + 6717321711.

It is an arithmetic number, because the mean of its divisors is an integer number (6717321711).

Almost surely, 2^13434643421 is an apocalyptic number.

It is an amenable number.

13434643421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13434643421 is an equidigital number, since it uses as much as digits as its factorization.

13434643421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 35.

The spelling of 13434643421 in words is "thirteen billion, four hundred thirty-four million, six hundred forty-three thousand, four hundred twenty-one".