121638738650265 has 48 divisors (see below), whose sum is σ = 216079230407040. Its totient is φ = 63263481826560.

The previous prime is 121638738650257. The next prime is 121638738650269. The reversal of 121638738650265 is 562056837836121.

121638738650265 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 38 + 7 + 38 + 6 + 502 + 65 = 666.

It is not a de Polignac number, because 121638738650265 - 2³ = 121638738650257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121638738650269) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10558245 + ... + 18834914.

It is an arithmetic number, because the mean of its divisors is an integer number (4501650633480).

Almost surely, 2^{121638738650265} is an apocalyptic number.

121638738650265 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121638738650265 is a deficient number, since it is larger than the sum of its proper divisors (94440491756775).

121638738650265 is a wasteful number, since it uses less digits than its factorization.

121638738650265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29395454 (or 29395451 counting only the distinct ones).

The product of its (nonzero) digits is 87091200, while the sum is 63.

The spelling of 121638738650265 in words is "one hundred twenty-one trillion, six hundred thirty-eight billion, seven hundred thirty-eight million, six hundred fifty thousand, two hundred sixty-five".