121616785 has 8 divisors (see below), whose sum is σ = 145999656. Its totient is φ = 97253760.

The previous prime is 121616773. The next prime is 121616797. The reversal of 121616785 is 587616121.

It is a Cunningham number, because it is equal to 11028²+1.

It is an interprime number because it is at equal distance from previous prime (121616773) and next prime (121616797).

It can be written as a sum of positive squares in 4 ways, for example, as 43771456 + 77845329 = 6616^2 + 8823^2 .

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

It is not a de Polignac number, because 121616785 - 2¹¹ = 121614737 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

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, 19467 + ... + 24943.

It is an arithmetic number, because the mean of its divisors is an integer number (18249957).

Almost surely, 2^121616785 is an apocalyptic number.

It is an amenable number.

121616785 is a deficient number, since it is larger than the sum of its proper divisors (24382871).

121616785 is an equidigital number, since it uses as much as digits as its factorization.

121616785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9923.

The product of its digits is 20160, while the sum is 37.

The square root of 121616785 is about 11028.0000453391. Note that the first 4 decimals coincide. The cubic root of 121616785 is about 495.4477260541.

The spelling of 121616785 in words is "one hundred twenty-one million, six hundred sixteen thousand, seven hundred eighty-five".