1261143 has 16 divisors (see below), whose sum is σ = 2012640. Its totient is φ = 775872.

The previous prime is 1261133. The next prime is 1261157. The reversal of 1261143 is 3411621.

It is a happy number.

1261143 is a `hidden beast` number, since 12 + 611 + 43 = 666.

It is not a de Polignac number, because 1261143 - 2⁶ = 1261079 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1446 + ... + 2147.

It is an arithmetic number, because the mean of its divisors is an integer number (125790).

2^1261143 is an apocalyptic number.

1261143 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1261143 is a deficient number, since it is larger than the sum of its proper divisors (751497).

1261143 is a wasteful number, since it uses less digits than its factorization.

1261143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3615 (or 3609 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1261143 is about 1123.0062332864. The cubic root of 1261143 is about 108.0408795863.

Adding to 1261143 its reverse (3411621), we get a palindrome (4672764).

The spelling of 1261143 in words is "one million, two hundred sixty-one thousand, one hundred forty-three".