21345320443373 has 2 divisors, whose sum is σ = 21345320443374. Its totient is φ = 21345320443372.

The previous prime is 21345320443333. The next prime is 21345320443439. The reversal of 21345320443373 is 37334402354312.

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., 20504939384644 + 840381058729 = 4528238^2 + 916723^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345320443373 - 2⁴² = 16947273932269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21345320443303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672660221686 + 10672660221687.

It is an arithmetic number, because the mean of its divisors is an integer number (10672660221687).

Almost surely, 2^{21345320443373} is an apocalyptic number.

It is an amenable number.

21345320443373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345320443373 is an equidigital number, since it uses as much as digits as its factorization.

21345320443373 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 44.

Adding to 21345320443373 its reverse (37334402354312), we get a palindrome (58679722797685).

The spelling of 21345320443373 in words is "twenty-one trillion, three hundred forty-five billion, three hundred twenty million, four hundred forty-three thousand, three hundred seventy-three".