21600641747 has 2 divisors, whose sum is σ = 21600641748. Its totient is φ = 21600641746.

The previous prime is 21600641731. The next prime is 21600641767. The reversal of 21600641747 is 74714600612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21600641747 - 2⁴ = 21600641731 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21600641747.

It is not a weakly prime, because it can be changed into another prime (21600641707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800320873 + 10800320874.

It is an arithmetic number, because the mean of its divisors is an integer number (10800320874).

Almost surely, 2^21600641747 is an apocalyptic number.

21600641747 is a deficient number, since it is larger than the sum of its proper divisors (1).

21600641747 is an equidigital number, since it uses as much as digits as its factorization.

21600641747 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 38.

The spelling of 21600641747 in words is "twenty-one billion, six hundred million, six hundred forty-one thousand, seven hundred forty-seven".