121818751997 has 12 divisors (see below), whose sum is σ = 136216931520. Its totient is φ = 108618572736.

The previous prime is 121818751913. The next prime is 121818752057. The reversal of 121818751997 is 799157818121.

It is not a de Polignac number, because 121818751997 - 2²⁴ = 121801974781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121818751297) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11087093 + ... + 11098074.

It is an arithmetic number, because the mean of its divisors is an integer number (11351410960).

Almost surely, 2^121818751997 is an apocalyptic number.

121818751997 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

121818751997 is a deficient number, since it is larger than the sum of its proper divisors (14398179523).

121818751997 is a wasteful number, since it uses less digits than its factorization.

121818751997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22185220 (or 22185203 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 59.

The spelling of 121818751997 in words is "one hundred twenty-one billion, eight hundred eighteen million, seven hundred fifty-one thousand, nine hundred ninety-seven".