121239865 has 8 divisors (see below), whose sum is σ = 150504840. Its totient is φ = 93647232.

The previous prime is 121239857. The next prime is 121239887. The reversal of 121239865 is 568932121.

It can be written as a sum of positive squares in 4 ways, for example, as 33686416 + 87553449 = 5804^2 + 9357^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121239865 - 2³ = 121239857 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 417924 + ... + 418213.

It is an arithmetic number, because the mean of its divisors is an integer number (18813105).

Almost surely, 2^121239865 is an apocalyptic number.

It is an amenable number.

121239865 is a deficient number, since it is larger than the sum of its proper divisors (29264975).

121239865 is an equidigital number, since it uses as much as digits as its factorization.

121239865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836171.

The product of its digits is 25920, while the sum is 37.

The square root of 121239865 is about 11010.8975565119. The cubic root of 121239865 is about 494.9353586984.

The spelling of 121239865 in words is "one hundred twenty-one million, two hundred thirty-nine thousand, eight hundred sixty-five".