1265530161 has 16 divisors (see below), whose sum is σ = 1929101184. Its totient is φ = 722907264.

The previous prime is 1265530157. The next prime is 1265530171. The reversal of 1265530161 is 1610355621.

It is not a de Polignac number, because 1265530161 - 2² = 1265530157 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1265530141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62845 + ... + 80501.

It is an arithmetic number, because the mean of its divisors is an integer number (120568824).

Almost surely, 2^1265530161 is an apocalyptic number.

It is an amenable number.

1265530161 is a deficient number, since it is larger than the sum of its proper divisors (663571023).

1265530161 is a wasteful number, since it uses less digits than its factorization.

1265530161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21080.

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1265530161 is about 35574.2907308073. The cubic root of 1265530161 is about 1081.6601584864.

Adding to 1265530161 its reverse (1610355621), we get a palindrome (2875885782).

The spelling of 1265530161 in words is "one billion, two hundred sixty-five million, five hundred thirty thousand, one hundred sixty-one".