1155261 has 4 divisors (see below), whose sum is σ = 1540352. Its totient is φ = 770172.

The previous prime is 1155247. The next prime is 1155263. The reversal of 1155261 is 1625511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1625511 = 3 ⋅541837.

It is not a de Polignac number, because 1155261 - 2¹⁷ = 1024189 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155263) 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, 192541 + ... + 192546.

It is an arithmetic number, because the mean of its divisors is an integer number (385088).

2^1155261 is an apocalyptic number.

It is an amenable number.

1155261 is a deficient number, since it is larger than the sum of its proper divisors (385091).

1155261 is an equidigital number, since it uses as much as digits as its factorization.

1155261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 385090.

The product of its digits is 300, while the sum is 21.

The square root of 1155261 is about 1074.8306843406. The cubic root of 1155261 is about 104.9284773692.

The spelling of 1155261 in words is "one million, one hundred fifty-five thousand, two hundred sixty-one".