121643568 has 180 divisors, whose sum is σ = 376111840. Its totient is φ = 36661248.

The previous prime is 121643539. The next prime is 121643569. The reversal of 121643568 is 865346121.

It is a happy number.

121643568 is a `hidden beast` number, since 1 + 2 + 1 + 643 + 5 + 6 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (121643569) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1539753 + ... + 1539831.

Almost surely, 2^121643568 is an apocalyptic number.

121643568 is a gapful number since it is divisible by the number (18) 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 121643568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (188055920).

121643568 is an abundant number, since it is smaller than the sum of its proper divisors (254468272).

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

121643568 is a wasteful number, since it uses less digits than its factorization.

121643568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164 (or 138 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 121643568 is about 11029.2142965852. The cubic root of 121643568 is about 495.4840932997.

Adding to 121643568 its reverse (865346121), we get a palindrome (986989689).

The spelling of 121643568 in words is "one hundred twenty-one million, six hundred forty-three thousand, five hundred sixty-eight".