12640052261 has 2 divisors, whose sum is σ = 12640052262. Its totient is φ = 12640052260.

The previous prime is 12640052209. The next prime is 12640052267. The reversal of 12640052261 is 16225004621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11314364161 + 1325688100 = 106369^2 + 36410^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640052261 - 2¹⁸ = 12639790117 is a prime.

It is a super-2 number, since 2×12640052261² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12640052267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6320026130 + 6320026131.

It is an arithmetic number, because the mean of its divisors is an integer number (6320026131).

Almost surely, 2^12640052261 is an apocalyptic number.

It is an amenable number.

12640052261 is a deficient number, since it is larger than the sum of its proper divisors (1).

12640052261 is an equidigital number, since it uses as much as digits as its factorization.

12640052261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 12640052261 its reverse (16225004621), we get a palindrome (28865056882).

The spelling of 12640052261 in words is "twelve billion, six hundred forty million, fifty-two thousand, two hundred sixty-one".