1231005339581 has 2 divisors, whose sum is σ = 1231005339582. Its totient is φ = 1231005339580.

The previous prime is 1231005339503. The next prime is 1231005339589. The reversal of 1231005339581 is 1859335001321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1209265311556 + 21740028025 = 1099666^2 + 147445^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231005339581 - 2³⁴ = 1213825470397 is a prime.

It is a super-2 number, since 2×1231005339581² (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 (1231005339589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615502669790 + 615502669791.

It is an arithmetic number, because the mean of its divisors is an integer number (615502669791).

Almost surely, 2^{1231005339581} is an apocalyptic number.

It is an amenable number.

1231005339581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231005339581 is an equidigital number, since it uses as much as digits as its factorization.

1231005339581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 97200, while the sum is 41.

The spelling of 1231005339581 in words is "one trillion, two hundred thirty-one billion, five million, three hundred thirty-nine thousand, five hundred eighty-one".