1281591 has 12 divisors (see below), whose sum is σ = 1865032. Its totient is φ = 848016.

The previous prime is 1281587. The next prime is 1281649. The reversal of 1281591 is 1951821.

It is not a de Polignac number, because 1281591 - 2² = 1281587 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 960 + ... + 1866.

2^1281591 is an apocalyptic number.

1281591 is a deficient number, since it is larger than the sum of its proper divisors (583441).

1281591 is a wasteful number, since it uses less digits than its factorization.

1281591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070 (or 1067 counting only the distinct ones).

The product of its digits is 720, while the sum is 27.

The square root of 1281591 is about 1132.0737608478. The cubic root of 1281591 is about 108.6216718550.

The spelling of 1281591 in words is "one million, two hundred eighty-one thousand, five hundred ninety-one".