121687786121 has 4 divisors (see below), whose sum is σ = 132750312144. Its totient is φ = 110625260100.

The previous prime is 121687786111. The next prime is 121687786223.

It is a happy number.

121687786121 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121687786121 - 2¹⁸ = 121687523977 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121687786121.

It is not an unprimeable number, because it can be changed into a prime (121687786111) 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, 5531262995 + ... + 5531263016.

It is an arithmetic number, because the mean of its divisors is an integer number (33187578036).

Almost surely, 2^121687786121 is an apocalyptic number.

121687786121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121687786121 is a deficient number, since it is larger than the sum of its proper divisors (11062526023).

121687786121 is a wasteful number, since it uses less digits than its factorization.

121687786121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11062526022.

The product of its digits is 451584, while the sum is 50.

The spelling of 121687786121 in words is "one hundred twenty-one billion, six hundred eighty-seven million, seven hundred eighty-six thousand, one hundred twenty-one".