21213545032513 has 2 divisors, whose sum is σ = 21213545032514. Its totient is φ = 21213545032512.

The previous prime is 21213545032501. The next prime is 21213545032529. The reversal of 21213545032513 is 31523054531212.

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., 15235774309809 + 5977770722704 = 3903303^2 + 2444948^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213545032513 - 2⁴¹ = 19014521776961 is a prime.

It is not a weakly prime, because it can be changed into another prime (21213545032573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606772516256 + 10606772516257.

It is an arithmetic number, because the mean of its divisors is an integer number (10606772516257).

Almost surely, 2^{21213545032513} is an apocalyptic number.

It is an amenable number.

21213545032513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213545032513 is an equidigital number, since it uses as much as digits as its factorization.

21213545032513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108000, while the sum is 37.

Adding to 21213545032513 its reverse (31523054531212), we get a palindrome (52736599563725).

The spelling of 21213545032513 in words is "twenty-one trillion, two hundred thirteen billion, five hundred forty-five million, thirty-two thousand, five hundred thirteen".