16865408121 has 16 divisors (see below), whose sum is σ = 23689800000. Its totient is φ = 10643263488.

The previous prime is 16865408107. The next prime is 16865408123. The reversal of 16865408121 is 12180456861.

It is not a de Polignac number, because 16865408121 - 2⁶ = 16865408057 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16865408123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47256 + ... + 189641.

It is an arithmetic number, because the mean of its divisors is an integer number (1480612500).

Almost surely, 2^16865408121 is an apocalyptic number.

It is an amenable number.

16865408121 is a deficient number, since it is larger than the sum of its proper divisors (6824391879).

16865408121 is a wasteful number, since it uses less digits than its factorization.

16865408121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238168.

The product of its (nonzero) digits is 92160, while the sum is 42.

The spelling of 16865408121 in words is "sixteen billion, eight hundred sixty-five million, four hundred eight thousand, one hundred twenty-one".