20420172681353 has 2 divisors, whose sum is σ = 20420172681354. Its totient is φ = 20420172681352.

The previous prime is 20420172681277. The next prime is 20420172681373. The reversal of 20420172681353 is 35318627102402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18511652535289 + 1908520146064 = 4302517^2 + 1381492^2 .

It is a cyclic number.

It is not a de Polignac number, because 20420172681353 - 2¹⁰ = 20420172680329 is a prime.

It is not a weakly prime, because it can be changed into another prime (20420172681373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210086340676 + 10210086340677.

It is an arithmetic number, because the mean of its divisors is an integer number (10210086340677).

Almost surely, 2^{20420172681353} is an apocalyptic number.

It is an amenable number.

20420172681353 is a deficient number, since it is larger than the sum of its proper divisors (1).

20420172681353 is an equidigital number, since it uses as much as digits as its factorization.

20420172681353 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 483840, while the sum is 44.

Adding to 20420172681353 its reverse (35318627102402), we get a palindrome (55738799783755).

The spelling of 20420172681353 in words is "twenty trillion, four hundred twenty billion, one hundred seventy-two million, six hundred eighty-one thousand, three hundred fifty-three".