21120577913 has 2 divisors, whose sum is σ = 21120577914. Its totient is φ = 21120577912.

The previous prime is 21120577879. The next prime is 21120577943. The reversal of 21120577913 is 31977502112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19367732224 + 1752845689 = 139168^2 + 41867^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120577913 - 2¹⁰ = 21120576889 is a prime.

It is a super-2 number, since 2×21120577913² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21120577943) 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, 10560288956 + 10560288957.

It is an arithmetic number, because the mean of its divisors is an integer number (10560288957).

Almost surely, 2^21120577913 is an apocalyptic number.

It is an amenable number.

21120577913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120577913 is an equidigital number, since it uses as much as digits as its factorization.

21120577913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460, while the sum is 38.

The spelling of 21120577913 in words is "twenty-one billion, one hundred twenty million, five hundred seventy-seven thousand, nine hundred thirteen".