1261313355251 has 2 divisors, whose sum is σ = 1261313355252. Its totient is φ = 1261313355250.

The previous prime is 1261313355223. The next prime is 1261313355257. The reversal of 1261313355251 is 1525533131621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1261313355251 - 2¹⁴ = 1261313338867 is a prime.

It is a super-2 number, since 2×1261313355251² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1261313355257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630656677625 + 630656677626.

It is an arithmetic number, because the mean of its divisors is an integer number (630656677626).

Almost surely, 2^{1261313355251} is an apocalyptic number.

1261313355251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261313355251 is an equidigital number, since it uses as much as digits as its factorization.

1261313355251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81000, while the sum is 38.

Adding to 1261313355251 its reverse (1525533131621), we get a palindrome (2786846486872).

The spelling of 1261313355251 in words is "one trillion, two hundred sixty-one billion, three hundred thirteen million, three hundred fifty-five thousand, two hundred fifty-one".