21345320473439 has 2 divisors, whose sum is σ = 21345320473440. Its totient is φ = 21345320473438.

The previous prime is 21345320473429. The next prime is 21345320473601. The reversal of 21345320473439 is 93437402354312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21345320473439 - 2⁴ = 21345320473423 is a prime.

It is a super-2 number, since 2×21345320473439² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21345320473429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672660236719 + 10672660236720.

It is an arithmetic number, because the mean of its divisors is an integer number (10672660236720).

Almost surely, 2^{21345320473439} is an apocalyptic number.

21345320473439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345320473439 is an equidigital number, since it uses as much as digits as its factorization.

21345320473439 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6531840, while the sum is 50.

The spelling of 21345320473439 in words is "twenty-one trillion, three hundred forty-five billion, three hundred twenty million, four hundred seventy-three thousand, four hundred thirty-nine".