21123542020337 has 2 divisors, whose sum is σ = 21123542020338. Its totient is φ = 21123542020336.

The previous prime is 21123542020313. The next prime is 21123542020349. The reversal of 21123542020337 is 73302024532112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15168033787456 + 5955508232881 = 3894616^2 + 2440391^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123542020337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123542020297 and 21123542020306.

It is not a weakly prime, because it can be changed into another prime (21123542022337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561771010168 + 10561771010169.

It is an arithmetic number, because the mean of its divisors is an integer number (10561771010169).

Almost surely, 2^{21123542020337} is an apocalyptic number.

It is an amenable number.

21123542020337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123542020337 is an equidigital number, since it uses as much as digits as its factorization.

21123542020337 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 35.

Adding to 21123542020337 its reverse (73302024532112), we get a palindrome (94425566552449).

The spelling of 21123542020337 in words is "twenty-one trillion, one hundred twenty-three billion, five hundred forty-two million, twenty thousand, three hundred thirty-seven".