121642165 has 4 divisors (see below), whose sum is σ = 145970604. Its totient is φ = 97313728.

The previous prime is 121642159. The next prime is 121642177. The reversal of 121642165 is 561246121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 561246121 = 1951 ⋅287671.

It can be written as a sum of positive squares in 2 ways, for example, as 13003236 + 108638929 = 3606^2 + 10423^2 .

It is a cyclic number.

It is not a de Polignac number, because 121642165 - 2²³ = 113253557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12164212 + ... + 12164221.

It is an arithmetic number, because the mean of its divisors is an integer number (36492651).

Almost surely, 2^121642165 is an apocalyptic number.

It is an amenable number.

121642165 is a deficient number, since it is larger than the sum of its proper divisors (24328439).

121642165 is an equidigital number, since it uses as much as digits as its factorization.

121642165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24328438.

The product of its digits is 2880, while the sum is 28.

The square root of 121642165 is about 11029.1506925964. The cubic root of 121642165 is about 495.4821883713.

Adding to 121642165 its reverse (561246121), we get a palindrome (682888286).

The spelling of 121642165 in words is "one hundred twenty-one million, six hundred forty-two thousand, one hundred sixty-five".