1165945121 has 16 divisors (see below), whose sum is σ = 1315491840. Its totient is φ = 1024230480.

The previous prime is 1165945117. The next prime is 1165945139. The reversal of 1165945121 is 1215495611.

It is a cyclic number.

It is not a de Polignac number, because 1165945121 - 2² = 1165945117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1165945021) 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, 26570 + ... + 55116.

It is an arithmetic number, because the mean of its divisors is an integer number (82218240).

Almost surely, 2^1165945121 is an apocalyptic number.

1165945121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1165945121 is a deficient number, since it is larger than the sum of its proper divisors (149546719).

1165945121 is a wasteful number, since it uses less digits than its factorization.

1165945121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28684.

The product of its digits is 10800, while the sum is 35.

The square root of 1165945121 is about 34145.9385725448. The cubic root of 1165945121 is about 1052.5095290483.

The spelling of 1165945121 in words is "one billion, one hundred sixty-five million, nine hundred forty-five thousand, one hundred twenty-one".