121686712357 has 24 divisors (see below), whose sum is σ = 144791443320. Its totient is φ = 101939160960.

The previous prime is 121686712271. The next prime is 121686712363. The reversal of 121686712357 is 753217686121.

It can be written as a sum of positive squares in 4 ways, for example, as 5655190401 + 116031521956 = 75201^2 + 340634^2 .

It is not a de Polignac number, because 121686712357 - 2¹⁵ = 121686679589 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

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 121686712357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121686712057) 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 23 ways as a sum of consecutive naturals, for example, 339619 + ... + 598927.

It is an arithmetic number, because the mean of its divisors is an integer number (6032976805).

Almost surely, 2^121686712357 is an apocalyptic number.

It is an amenable number.

121686712357 is a deficient number, since it is larger than the sum of its proper divisors (23104730963).

121686712357 is a wasteful number, since it uses less digits than its factorization.

121686712357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259541 (or 259534 counting only the distinct ones).

The product of its digits is 846720, while the sum is 49.

The spelling of 121686712357 in words is "one hundred twenty-one billion, six hundred eighty-six million, seven hundred twelve thousand, three hundred fifty-seven".