121205617506 has 12 divisors (see below), whose sum is σ = 262612171302. Its totient is φ = 40401872496.

The previous prime is 121205617469. The next prime is 121205617523. The reversal of 121205617506 is 605716502121.

121205617506 is a `hidden beast` number, since 1 + 2 + 1 + 20 + 561 + 75 + 0 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 90513731025 + 30691886481 = 300855^2 + 175191^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3366822691 + ... + 3366822726.

Almost surely, 2^121205617506 is an apocalyptic number.

121205617506 is an abundant number, since it is smaller than the sum of its proper divisors (141406553796).

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

121205617506 is a wasteful number, since it uses less digits than its factorization.

121205617506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6733645425 (or 6733645422 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 121205617506 in words is "one hundred twenty-one billion, two hundred five million, six hundred seventeen thousand, five hundred six".