21455000502209 has 2 divisors, whose sum is σ = 21455000502210. Its totient is φ = 21455000502208.

The previous prime is 21455000502119. The next prime is 21455000502217. The reversal of 21455000502209 is 90220500055412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20469652435600 + 985348066609 = 4524340^2 + 992647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21455000502209 - 2¹⁶ = 21455000436673 is a prime.

It is not a weakly prime, because it can be changed into another prime (21455000508209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727500251104 + 10727500251105.

It is an arithmetic number, because the mean of its divisors is an integer number (10727500251105).

Almost surely, 2^{21455000502209} is an apocalyptic number.

It is an amenable number.

21455000502209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21455000502209 is an equidigital number, since it uses as much as digits as its factorization.

21455000502209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36000, while the sum is 35.

The spelling of 21455000502209 in words is "twenty-one trillion, four hundred fifty-five billion, five hundred two thousand, two hundred nine".