21536366057 has 2 divisors, whose sum is σ = 21536366058. Its totient is φ = 21536366056.

The previous prime is 21536366053. The next prime is 21536366081. The reversal of 21536366057 is 75066363512.

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., 16878167056 + 4658199001 = 129916^2 + 68251^2 .

It is a cyclic number.

It is not a de Polignac number, because 21536366057 - 2² = 21536366053 is a prime.

It is a super-2 number, since 2×21536366057² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21536365999 and 21536366017.

It is not a weakly prime, because it can be changed into another prime (21536366051) 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, 10768183028 + 10768183029.

It is an arithmetic number, because the mean of its divisors is an integer number (10768183029).

Almost surely, 2^21536366057 is an apocalyptic number.

It is an amenable number.

21536366057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21536366057 is an equidigital number, since it uses as much as digits as its factorization.

21536366057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 680400, while the sum is 44.

The spelling of 21536366057 in words is "twenty-one billion, five hundred thirty-six million, three hundred sixty-six thousand, fifty-seven".