121221165 has 24 divisors (see below), whose sum is σ = 210025440. Its totient is φ = 59676864.

The previous prime is 121221103. The next prime is 121221167. The reversal of 121221165 is 561122121.

It is not a de Polignac number, because 121221165 - 2²³ = 112832557 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221167) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21375 + ... + 26444.

It is an arithmetic number, because the mean of its divisors is an integer number (8751060).

Almost surely, 2^121221165 is an apocalyptic number.

121221165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121221165 is a deficient number, since it is larger than the sum of its proper divisors (88804275).

121221165 is a wasteful number, since it uses less digits than its factorization.

121221165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47853 (or 47840 counting only the distinct ones).

The product of its digits is 240, while the sum is 21.

The square root of 121221165 is about 11010.0483650164. The cubic root of 121221165 is about 494.9099111635.

Adding to 121221165 its reverse (561122121), we get a palindrome (682343286).

It can be divided in two parts, 12122116 and 5, that added together give a palindrome (12122121).

The spelling of 121221165 in words is "one hundred twenty-one million, two hundred twenty-one thousand, one hundred sixty-five".