1215331161 has 16 divisors (see below), whose sum is σ = 1824780288. Its totient is φ = 712803600.

The previous prime is 1215331141. The next prime is 1215331163. The reversal of 1215331161 is 1611335121.

It is not a de Polignac number, because 1215331161 - 2¹⁴ = 1215314777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1215331163) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 592981 + ... + 595026.

It is an arithmetic number, because the mean of its divisors is an integer number (114048768).

Almost surely, 2^1215331161 is an apocalyptic number.

1215331161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1215331161 is a deficient number, since it is larger than the sum of its proper divisors (609449127).

1215331161 is a wasteful number, since it uses less digits than its factorization.

1215331161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1188052.

The product of its digits is 540, while the sum is 24.

The square root of 1215331161 is about 34861.6000923652. The cubic root of 1215331161 is about 1067.1649293999.

Adding to 1215331161 its reverse (1611335121), we get a palindrome (2826666282).

The spelling of 1215331161 in words is "one billion, two hundred fifteen million, three hundred thirty-one thousand, one hundred sixty-one".