21103201278563 has 2 divisors, whose sum is σ = 21103201278564. Its totient is φ = 21103201278562.

The previous prime is 21103201278503. The next prime is 21103201278613. The reversal of 21103201278563 is 36587210230112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21103201278563 - 2¹⁸ = 21103201016419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21103201278563.

It is not a weakly prime, because it can be changed into another prime (21103201278503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551600639281 + 10551600639282.

It is an arithmetic number, because the mean of its divisors is an integer number (10551600639282).

Almost surely, 2^{21103201278563} is an apocalyptic number.

21103201278563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103201278563 is an equidigital number, since it uses as much as digits as its factorization.

21103201278563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The spelling of 21103201278563 in words is "twenty-one trillion, one hundred three billion, two hundred one million, two hundred seventy-eight thousand, five hundred sixty-three".