121565601 has 24 divisors (see below), whose sum is σ = 185492736. Its totient is φ = 76597920.

The previous prime is 121565599. The next prime is 121565617. The reversal of 121565601 is 106565121.

It is a happy number.

121565601 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 656 + 0 + 1 = 666.

It is not a de Polignac number, because 121565601 - 2¹ = 121565599 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121565201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6931 + ... + 17063.

It is an arithmetic number, because the mean of its divisors is an integer number (7728864).

Almost surely, 2^121565601 is an apocalyptic number.

It is an amenable number.

121565601 is a deficient number, since it is larger than the sum of its proper divisors (63927135).

121565601 is a wasteful number, since it uses less digits than its factorization.

121565601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10213 (or 10210 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 121565601 is about 11025.6791627546. The cubic root of 121565601 is about 495.3782111024.

The spelling of 121565601 in words is "one hundred twenty-one million, five hundred sixty-five thousand, six hundred one".