12605991857 has 2 divisors, whose sum is σ = 12605991858. Its totient is φ = 12605991856.

The previous prime is 12605991779. The next prime is 12605991949. The reversal of 12605991857 is 75819950621.

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., 11603382961 + 1002608896 = 107719^2 + 31664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12605991857 is a prime.

It is a super-2 number, since 2×12605991857² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12605991799 and 12605991808.

It is not a weakly prime, because it can be changed into another prime (12605991557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6302995928 + 6302995929.

It is an arithmetic number, because the mean of its divisors is an integer number (6302995929).

Almost surely, 2^12605991857 is an apocalyptic number.

It is an amenable number.

12605991857 is a deficient number, since it is larger than the sum of its proper divisors (1).

12605991857 is an equidigital number, since it uses as much as digits as its factorization.

12605991857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1360800, while the sum is 53.

The spelling of 12605991857 in words is "twelve billion, six hundred five million, nine hundred ninety-one thousand, eight hundred fifty-seven".