21445457288209 has 2 divisors, whose sum is σ = 21445457288210. Its totient is φ = 21445457288208.

The previous prime is 21445457288173. The next prime is 21445457288287. The reversal of 21445457288209 is 90288275454412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17427677574609 + 4017779713600 = 4174647^2 + 2004440^2 .

It is a cyclic number.

It is not a de Polignac number, because 21445457288209 - 2¹³ = 21445457280017 is a prime.

It is not a weakly prime, because it can be changed into another prime (21445457288009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722728644104 + 10722728644105.

It is an arithmetic number, because the mean of its divisors is an integer number (10722728644105).

Almost surely, 2^{21445457288209} is an apocalyptic number.

It is an amenable number.

21445457288209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21445457288209 is an equidigital number, since it uses as much as digits as its factorization.

21445457288209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51609600, while the sum is 61.

The spelling of 21445457288209 in words is "twenty-one trillion, four hundred forty-five billion, four hundred fifty-seven million, two hundred eighty-eight thousand, two hundred nine".