1305981 has 6 divisors (see below), whose sum is σ = 1886430. Its totient is φ = 870648.

The previous prime is 1305971. The next prime is 1306001. The reversal of 1305981 is 1895031.

It can be written as a sum of positive squares in only one way, i.e., 756900 + 549081 = 870^2 + 741^2 .

It is not a de Polignac number, because 1305981 - 2¹⁰ = 1304957 is a prime.

It is a super-2 number, since 2×1305981² = 3411172744722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1305961) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72546 + ... + 72563.

It is an arithmetic number, because the mean of its divisors is an integer number (314405).

2^1305981 is an apocalyptic number.

It is an amenable number.

1305981 is a deficient number, since it is larger than the sum of its proper divisors (580449).

1305981 is a wasteful number, since it uses less digits than its factorization.

1305981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145115 (or 145112 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 1305981 is about 1142.7952572530. The cubic root of 1305981 is about 109.3064071689.

The spelling of 1305981 in words is "one million, three hundred five thousand, nine hundred eighty-one".