121638738650207 has 4 divisors (see below), whose sum is σ = 121638770120616. Its totient is φ = 121638707179800.

The previous prime is 121638738650203. The next prime is 121638738650239. The reversal of 121638738650207 is 702056837836121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121638738650207 - 2² = 121638738650203 is a prime.

It is a super-2 number, since 2×121638738650207² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121638738650203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8967044 + ... + 17991257.

It is an arithmetic number, because the mean of its divisors is an integer number (30409692530154).

Almost surely, 2^{121638738650207} is an apocalyptic number.

121638738650207 is a deficient number, since it is larger than the sum of its proper divisors (31470409).

121638738650207 is an equidigital number, since it uses as much as digits as its factorization.

121638738650207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31470408.

The product of its (nonzero) digits is 20321280, while the sum is 59.

The spelling of 121638738650207 in words is "one hundred twenty-one trillion, six hundred thirty-eight billion, seven hundred thirty-eight million, six hundred fifty thousand, two hundred seven".