12650777921 has 2 divisors, whose sum is σ = 12650777922. Its totient is φ = 12650777920.

The previous prime is 12650777903. The next prime is 12650777933. The reversal of 12650777921 is 12977705621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8645280400 + 4005497521 = 92980^2 + 63289^2 .

It is an emirp because it is prime and its reverse (12977705621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12650777921 - 2¹⁸ = 12650515777 is a prime.

It is a super-2 number, since 2×12650777921² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12650777021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6325388960 + 6325388961.

It is an arithmetic number, because the mean of its divisors is an integer number (6325388961).

Almost surely, 2^12650777921 is an apocalyptic number.

It is an amenable number.

12650777921 is a deficient number, since it is larger than the sum of its proper divisors (1).

12650777921 is an equidigital number, since it uses as much as digits as its factorization.

12650777921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 370440, while the sum is 47.

The spelling of 12650777921 in words is "twelve billion, six hundred fifty million, seven hundred seventy-seven thousand, nine hundred twenty-one".