21636460061 has 2 divisors, whose sum is σ = 21636460062. Its totient is φ = 21636460060.

The previous prime is 21636460051. The next prime is 21636460073. The reversal of 21636460061 is 16006463612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21084492025 + 551968036 = 145205^2 + 23494^2 .

It is a cyclic number.

It is not a de Polignac number, because 21636460061 - 2³⁴ = 4456590877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21636460051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10818230030 + 10818230031.

It is an arithmetic number, because the mean of its divisors is an integer number (10818230031).

Almost surely, 2^21636460061 is an apocalyptic number.

It is an amenable number.

21636460061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21636460061 is an equidigital number, since it uses as much as digits as its factorization.

21636460061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 35.

The spelling of 21636460061 in words is "twenty-one billion, six hundred thirty-six million, four hundred sixty thousand, sixty-one".