21488044681409 has 2 divisors, whose sum is σ = 21488044681410. Its totient is φ = 21488044681408.

The previous prime is 21488044681403. The next prime is 21488044681459. The reversal of 21488044681409 is 90418644088412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17285429880625 + 4202614800784 = 4157575^2 + 2050028^2 .

It is a cyclic number.

It is not a de Polignac number, because 21488044681409 - 2⁴⁰ = 20388533053633 is a prime.

It is a super-2 number, since 2×21488044681409² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21488044681403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10744022340704 + 10744022340705.

It is an arithmetic number, because the mean of its divisors is an integer number (10744022340705).

Almost surely, 2^{21488044681409} is an apocalyptic number.

It is an amenable number.

21488044681409 is a deficient number, since it is larger than the sum of its proper divisors (1).

21488044681409 is an equidigital number, since it uses as much as digits as its factorization.

21488044681409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14155776, while the sum is 59.

The spelling of 21488044681409 in words is "twenty-one trillion, four hundred eighty-eight billion, forty-four million, six hundred eighty-one thousand, four hundred nine".