1261365 has 32 divisors (see below), whose sum is σ = 2370816. Its totient is φ = 560640.

The previous prime is 1261363. The next prime is 1261373. The reversal of 1261365 is 5631621.

1261365 = 71² + 72² + ... + 160².

It is not a de Polignac number, because 1261365 - 2¹ = 1261363 is a prime.

It is an Ulam number.

1261365 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261363) 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 31 ways as a sum of consecutive naturals, for example, 4159 + ... + 4451.

It is an arithmetic number, because the mean of its divisors is an integer number (74088).

2^1261365 is an apocalyptic number.

1261365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261365 is a deficient number, since it is larger than the sum of its proper divisors (1109451).

1261365 is a wasteful number, since it uses less digits than its factorization.

1261365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349.

The product of its digits is 1080, while the sum is 24.

The square root of 1261365 is about 1123.1050707748. The cubic root of 1261365 is about 108.0472187215.

Adding to 1261365 its reverse (5631621), we get a palindrome (6892986).

The spelling of 1261365 in words is "one million, two hundred sixty-one thousand, three hundred sixty-five".