121861121 has 4 divisors (see below), whose sum is σ = 122939652. Its totient is φ = 120782592.

The previous prime is 121861109. The next prime is 121861127. The reversal of 121861121 is 121168121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121168121 = 3511 ⋅34511.

It can be written as a sum of positive squares in 2 ways, for example, as 2265025 + 119596096 = 1505^2 + 10936^2 .

It is a cyclic number.

It is not a de Polignac number, because 121861121 - 2⁶ = 121861057 is a prime.

It is a super-2 number, since 2×121861121² = 29700265622753282, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121861127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 539096 + ... + 539321.

It is an arithmetic number, because the mean of its divisors is an integer number (30734913).

Almost surely, 2^121861121 is an apocalyptic number.

It is an amenable number.

121861121 is a deficient number, since it is larger than the sum of its proper divisors (1078531).

121861121 is a wasteful number, since it uses less digits than its factorization.

121861121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078530.

The product of its digits is 192, while the sum is 23.

The square root of 121861121 is about 11039.0724700946. The cubic root of 121861121 is about 495.7792996286.

The spelling of 121861121 in words is "one hundred twenty-one million, eight hundred sixty-one thousand, one hundred twenty-one".