21403420042349 has 2 divisors, whose sum is σ = 21403420042350. Its totient is φ = 21403420042348.

The previous prime is 21403420042331. The next prime is 21403420042397. The reversal of 21403420042349 is 94324002430412.

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., 17547871804324 + 3855548238025 = 4189018^2 + 1963555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21403420042349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21403420042549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701710021174 + 10701710021175.

It is an arithmetic number, because the mean of its divisors is an integer number (10701710021175).

Almost surely, 2^{21403420042349} is an apocalyptic number.

It is an amenable number.

21403420042349 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403420042349 is an equidigital number, since it uses as much as digits as its factorization.

21403420042349 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 38.

The spelling of 21403420042349 in words is "twenty-one trillion, four hundred three billion, four hundred twenty million, forty-two thousand, three hundred forty-nine".