20645512101563 has 2 divisors, whose sum is σ = 20645512101564. Its totient is φ = 20645512101562.

The previous prime is 20645512101449. The next prime is 20645512101601. The reversal of 20645512101563 is 36510121554602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20645512101563 - 2¹⁴ = 20645512085179 is a prime.

It is a super-3 number, since 3×20645512101563³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20645512101563.

It is not a weakly prime, because it can be changed into another prime (20645512106563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322756050781 + 10322756050782.

It is an arithmetic number, because the mean of its divisors is an integer number (10322756050782).

Almost surely, 2^{20645512101563} is an apocalyptic number.

20645512101563 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645512101563 is an equidigital number, since it uses as much as digits as its factorization.

20645512101563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216000, while the sum is 41.

The spelling of 20645512101563 in words is "twenty trillion, six hundred forty-five billion, five hundred twelve million, one hundred one thousand, five hundred sixty-three".