21027575356709 has 2 divisors, whose sum is σ = 21027575356710. Its totient is φ = 21027575356708.

The previous prime is 21027575356673. The next prime is 21027575356817. The reversal of 21027575356709 is 90765357572012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11464928280100 + 9562647076609 = 3385990^2 + 3092353^2 .

It is a cyclic number.

It is not a de Polignac number, because 21027575356709 - 2²⁰ = 21027574308133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21027575356409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10513787678354 + 10513787678355.

It is an arithmetic number, because the mean of its divisors is an integer number (10513787678355).

Almost surely, 2^{21027575356709} is an apocalyptic number.

It is an amenable number.

21027575356709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21027575356709 is an equidigital number, since it uses as much as digits as its factorization.

21027575356709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27783000, while the sum is 59.

The spelling of 21027575356709 in words is "twenty-one trillion, twenty-seven billion, five hundred seventy-five million, three hundred fifty-six thousand, seven hundred nine".