1281658271581 has 2 divisors, whose sum is σ = 1281658271582. Its totient is φ = 1281658271580.

The previous prime is 1281658271513. The next prime is 1281658271591. The reversal of 1281658271581 is 1851728561821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1252317664900 + 29340606681 = 1119070^2 + 171291^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281658271581 - 2²³ = 1281649882973 is a prime.

It is a super-2 number, since 2×1281658271581² (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 (1281658271591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640829135790 + 640829135791.

It is an arithmetic number, because the mean of its divisors is an integer number (640829135791).

Almost surely, 2^{1281658271581} is an apocalyptic number.

It is an amenable number.

1281658271581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281658271581 is an equidigital number, since it uses as much as digits as its factorization.

1281658271581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2150400, while the sum is 55.

The spelling of 1281658271581 in words is "one trillion, two hundred eighty-one billion, six hundred fifty-eight million, two hundred seventy-one thousand, five hundred eighty-one".