21645132049 has 2 divisors, whose sum is σ = 21645132050. Its totient is φ = 21645132048.

The previous prime is 21645132011. The next prime is 21645132079. The reversal of 21645132049 is 94023154612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19495140625 + 2149991424 = 139625^2 + 46368^2 .

It is a cyclic number.

It is not a de Polignac number, because 21645132049 - 2²³ = 21636743441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21645131999 and 21645132017.

It is not a weakly prime, because it can be changed into another prime (21645132079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10822566024 + 10822566025.

It is an arithmetic number, because the mean of its divisors is an integer number (10822566025).

Almost surely, 2^21645132049 is an apocalyptic number.

It is an amenable number.

21645132049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21645132049 is an equidigital number, since it uses as much as digits as its factorization.

21645132049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21645132049 in words is "twenty-one billion, six hundred forty-five million, one hundred thirty-two thousand, forty-nine".