121655125205 has 4 divisors (see below), whose sum is σ = 145986150252. Its totient is φ = 97324100160.

The previous prime is 121655125201. The next prime is 121655125211. The reversal of 121655125205 is 502521556121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17864193649 + 103790931556 = 133657^2 + 322166^2 .

It is not a de Polignac number, because 121655125205 - 2² = 121655125201 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121655125201) 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, 12165512516 + ... + 12165512525.

It is an arithmetic number, because the mean of its divisors is an integer number (36496537563).

Almost surely, 2^121655125205 is an apocalyptic number.

It is an amenable number.

121655125205 is a deficient number, since it is larger than the sum of its proper divisors (24331025047).

121655125205 is an equidigital number, since it uses as much as digits as its factorization.

121655125205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24331025046.

The product of its (nonzero) digits is 30000, while the sum is 35.

The spelling of 121655125205 in words is "one hundred twenty-one billion, six hundred fifty-five million, one hundred twenty-five thousand, two hundred five".