21536343373 has 2 divisors, whose sum is σ = 21536343374. Its totient is φ = 21536343372.

The previous prime is 21536343289. The next prime is 21536343407. The reversal of 21536343373 is 37334363512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20990793924 + 545549449 = 144882^2 + 23357^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21536343373 is a prime.

It is a super-2 number, since 2×21536343373² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21536343473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10768171686 + 10768171687.

It is an arithmetic number, because the mean of its divisors is an integer number (10768171687).

Almost surely, 2^21536343373 is an apocalyptic number.

It is an amenable number.

21536343373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21536343373 is an equidigital number, since it uses as much as digits as its factorization.

21536343373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 40.

The spelling of 21536343373 in words is "twenty-one billion, five hundred thirty-six million, three hundred forty-three thousand, three hundred seventy-three".