1261311 has 8 divisors (see below), whose sum is σ = 1686960. Its totient is φ = 838272.

The previous prime is 1261301. The next prime is 1261313. The reversal of 1261311 is 1131621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1261311 - 2⁵ = 1261279 is a prime.

It is an Ulam number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1425 + ... + 2133.

It is an arithmetic number, because the mean of its divisors is an integer number (210870).

2^1261311 is an apocalyptic number.

1261311 is a deficient number, since it is larger than the sum of its proper divisors (425649).

1261311 is an equidigital number, since it uses as much as digits as its factorization.

1261311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305.

The product of its digits is 36, while the sum is 15.

The square root of 1261311 is about 1123.0810300241. The cubic root of 1261311 is about 108.0456768381.

Adding to 1261311 its reverse (1131621), we get a palindrome (2392932).

The spelling of 1261311 in words is "one million, two hundred sixty-one thousand, three hundred eleven".