21116204444537 has 2 divisors, whose sum is σ = 21116204444538. Its totient is φ = 21116204444536.

The previous prime is 21116204444513. The next prime is 21116204444603. The reversal of 21116204444537 is 73544440261112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20346270147856 + 769934296681 = 4510684^2 + 877459^2 .

It is a cyclic number.

It is not a de Polignac number, because 21116204444537 - 2³⁶ = 21047484967801 is a prime.

It is not a weakly prime, because it can be changed into another prime (21116204440537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10558102222268 + 10558102222269.

It is an arithmetic number, because the mean of its divisors is an integer number (10558102222269).

Almost surely, 2^{21116204444537} is an apocalyptic number.

It is an amenable number.

21116204444537 is a deficient number, since it is larger than the sum of its proper divisors (1).

21116204444537 is an equidigital number, since it uses as much as digits as its factorization.

21116204444537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 645120, while the sum is 44.

The spelling of 21116204444537 in words is "twenty-one trillion, one hundred sixteen billion, two hundred four million, four hundred forty-four thousand, five hundred thirty-seven".