21446217563 has 2 divisors, whose sum is σ = 21446217564. Its totient is φ = 21446217562.

The previous prime is 21446217493. The next prime is 21446217577. The reversal of 21446217563 is 36571264412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21446217563 - 2³⁴ = 4266348379 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21446217563.

It is not a weakly prime, because it can be changed into another prime (21446217763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723108781 + 10723108782.

It is an arithmetic number, because the mean of its divisors is an integer number (10723108782).

Almost surely, 2^21446217563 is an apocalyptic number.

21446217563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21446217563 is an equidigital number, since it uses as much as digits as its factorization.

21446217563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 41.

The spelling of 21446217563 in words is "twenty-one billion, four hundred forty-six million, two hundred seventeen thousand, five hundred sixty-three".