1115161261 has 2 divisors, whose sum is σ = 1115161262. Its totient is φ = 1115161260.

The previous prime is 1115161247. The next prime is 1115161297. The reversal of 1115161261 is 1621615111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1115159236 + 2025 = 33394^2 + 45^2 .

It is a cyclic number.

It is not a de Polignac number, because 1115161261 - 2¹⁹ = 1114636973 is a prime.

It is a super-2 number, since 2×1115161261² = 2487169276070220242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1115164261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 557580630 + 557580631.

It is an arithmetic number, because the mean of its divisors is an integer number (557580631).

Almost surely, 2^1115161261 is an apocalyptic number.

It is an amenable number.

1115161261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1115161261 is an equidigital number, since it uses as much as digits as its factorization.

1115161261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 25.

The square root of 1115161261 is about 33394.0303198042. The cubic root of 1115161261 is about 1037.0011183746.

Adding to 1115161261 its reverse (1621615111), we get a palindrome (2736776372).

The spelling of 1115161261 in words is "one billion, one hundred fifteen million, one hundred sixty-one thousand, two hundred sixty-one".