1261511 has 4 divisors (see below), whose sum is σ = 1267392. Its totient is φ = 1255632.

The previous prime is 1261489. The next prime is 1261523. The reversal of 1261511 is 1151621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1261511 - 2¹⁰ = 1260487 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2606 + ... + 3051.

It is an arithmetic number, because the mean of its divisors is an integer number (316848).

2^1261511 is an apocalyptic number.

1261511 is a deficient number, since it is larger than the sum of its proper divisors (5881).

1261511 is an equidigital number, since it uses as much as digits as its factorization.

1261511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5880.

The product of its digits is 60, while the sum is 17.

The square root of 1261511 is about 1123.1700672650. The cubic root of 1261511 is about 108.0513872969.

The spelling of 1261511 in words is "one million, two hundred sixty-one thousand, five hundred eleven".