20819773556453 has 2 divisors, whose sum is σ = 20819773556454. Its totient is φ = 20819773556452.

The previous prime is 20819773556443. The next prime is 20819773556531. The reversal of 20819773556453 is 35465537791802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19456374039844 + 1363399516609 = 4410938^2 + 1167647^2 .

It is a cyclic number.

It is not a de Polignac number, because 20819773556453 - 2³⁰ = 20818699814629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20819773556453.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20819773556443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10409886778226 + 10409886778227.

It is an arithmetic number, because the mean of its divisors is an integer number (10409886778227).

It is a 1-persistent number, because it is pandigital, but 2⋅20819773556453 = 41639547112906 is not.

Almost surely, 2^{20819773556453} is an apocalyptic number.

It is an amenable number.

20819773556453 is a deficient number, since it is larger than the sum of its proper divisors (1).

20819773556453 is an equidigital number, since it uses as much as digits as its factorization.

20819773556453 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512000, while the sum is 65.

The spelling of 20819773556453 in words is "twenty trillion, eight hundred nineteen billion, seven hundred seventy-three million, five hundred fifty-six thousand, four hundred fifty-three".