21063135761 has 2 divisors, whose sum is σ = 21063135762. Its totient is φ = 21063135760.

The previous prime is 21063135757. The next prime is 21063135791. The reversal of 21063135761 is 16753136012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18681695761 + 2381440000 = 136681^2 + 48800^2 .

It is a cyclic number.

It is not a de Polignac number, because 21063135761 - 2² = 21063135757 is a prime.

It is not a weakly prime, because it can be changed into another prime (21063135791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10531567880 + 10531567881.

It is an arithmetic number, because the mean of its divisors is an integer number (10531567881).

Almost surely, 2^21063135761 is an apocalyptic number.

It is an amenable number.

21063135761 is a deficient number, since it is larger than the sum of its proper divisors (1).

21063135761 is an equidigital number, since it uses as much as digits as its factorization.

21063135761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 35.

The spelling of 21063135761 in words is "twenty-one billion, sixty-three million, one hundred thirty-five thousand, seven hundred sixty-one".