21727550547709 has 2 divisors, whose sum is σ = 21727550547710. Its totient is φ = 21727550547708.

The previous prime is 21727550547667. The next prime is 21727550547743. The reversal of 21727550547709 is 90774505572712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12231261171684 + 9496289376025 = 3497322^2 + 3081605^2 .

It is a cyclic number.

It is not a de Polignac number, because 21727550547709 - 2¹¹ = 21727550545661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21727550544709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10863775273854 + 10863775273855.

It is an arithmetic number, because the mean of its divisors is an integer number (10863775273855).

Almost surely, 2^{21727550547709} is an apocalyptic number.

It is an amenable number.

21727550547709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21727550547709 is an equidigital number, since it uses as much as digits as its factorization.

21727550547709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43218000, while the sum is 61.

The spelling of 21727550547709 in words is "twenty-one trillion, seven hundred twenty-seven billion, five hundred fifty million, five hundred forty-seven thousand, seven hundred nine".