1306111026581 has 2 divisors, whose sum is σ = 1306111026582. Its totient is φ = 1306111026580.

The previous prime is 1306111026487. The next prime is 1306111026587. The reversal of 1306111026581 is 1856201116031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1145041244356 + 161069782225 = 1070066^2 + 401335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1306111026581 is a prime.

It is a super-2 number, since 2×1306111026581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1306111026587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 653055513290 + 653055513291.

It is an arithmetic number, because the mean of its divisors is an integer number (653055513291).

Almost surely, 2^{1306111026581} is an apocalyptic number.

It is an amenable number.

1306111026581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1306111026581 is an equidigital number, since it uses as much as digits as its factorization.

1306111026581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 35.

The spelling of 1306111026581 in words is "one trillion, three hundred six billion, one hundred eleven million, twenty-six thousand, five hundred eighty-one".