12121897638 has 8 divisors (see below), whose sum is σ = 24243795288. Its totient is φ = 4040632544.

The previous prime is 12121897637. The next prime is 12121897657. The reversal of 12121897638 is 83679812121.

12121897638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

12121897638 is an admirable number.

It is a super-2 number, since 2×12121897638² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121897631) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1010158131 + ... + 1010158142.

It is an arithmetic number, because the mean of its divisors is an integer number (3030474411).

Almost surely, 2^12121897638 is an apocalyptic number.

12121897638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12121897638 is a wasteful number, since it uses less digits than its factorization.

12121897638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020316278.

The product of its digits is 290304, while the sum is 48.

The spelling of 12121897638 in words is "twelve billion, one hundred twenty-one million, eight hundred ninety-seven thousand, six hundred thirty-eight".