121606561 has 8 divisors (see below), whose sum is σ = 122834880. Its totient is φ = 120384528.

The previous prime is 121606553. The next prime is 121606567. The reversal of 121606561 is 165606121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121606561 - 2³ = 121606553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121606567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43570 + ... + 46276.

It is an arithmetic number, because the mean of its divisors is an integer number (15354360).

Almost surely, 2^121606561 is an apocalyptic number.

It is an amenable number.

121606561 is a deficient number, since it is larger than the sum of its proper divisors (1228319).

121606561 is a wasteful number, since it uses less digits than its factorization.

121606561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3143.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 121606561 is about 11027.5364882643. The cubic root of 121606561 is about 495.4338420070.

It can be divided in two parts, 12160 and 6561, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 121606561 in words is "one hundred twenty-one million, six hundred six thousand, five hundred sixty-one".