121665287 has 8 divisors (see below), whose sum is σ = 125194800. Its totient is φ = 118148544.

The previous prime is 121665283. The next prime is 121665317. The reversal of 121665287 is 782566121.

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 121665287 - 2² = 121665283 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121665287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121665283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18164 + ... + 23942.

It is an arithmetic number, because the mean of its divisors is an integer number (15649350).

Almost surely, 2^121665287 is an apocalyptic number.

121665287 is a deficient number, since it is larger than the sum of its proper divisors (3529513).

121665287 is an equidigital number, since it uses as much as digits as its factorization.

121665287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6385.

The product of its digits is 40320, while the sum is 38.

The square root of 121665287 is about 11030.1988649344. The cubic root of 121665287 is about 495.5135804831.

The spelling of 121665287 in words is "one hundred twenty-one million, six hundred sixty-five thousand, two hundred eighty-seven".