121565600 has 72 divisors (see below), whose sum is σ = 319627980. Its totient is φ = 44881920.

The previous prime is 121565599. The next prime is 121565617. The reversal of 121565600 is 6565121.

It can be written as a sum of positive squares in 6 ways, for example, as 61905424 + 59660176 = 7868^2 + 7724^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a zygodrome in base 5.

It is a self number, because there is not a number n which added to its sum of digits gives 121565600.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4556 + ... + 16244.

Almost surely, 2^121565600 is an apocalyptic number.

121565600 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121565600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159813990).

121565600 is an abundant number, since it is smaller than the sum of its proper divisors (198062380).

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

121565600 is a wasteful number, since it uses less digits than its factorization.

121565600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11722 (or 11709 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 121565600 is about 11025.6791174059. The cubic root of 121565600 is about 495.3782097441.

The spelling of 121565600 in words is "one hundred twenty-one million, five hundred sixty-five thousand, six hundred".