121635378 has 64 divisors (see below), whose sum is σ = 287539200. Its totient is φ = 38005200.

The previous prime is 121635361. The next prime is 121635379. The reversal of 121635378 is 873536121.

121635378 is a `hidden beast` number, since 12 + 1 + 635 + 3 + 7 + 8 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121635379) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 105103 + ... + 106253.

It is an arithmetic number, because the mean of its divisors is an integer number (4492800).

Almost surely, 2^121635378 is an apocalyptic number.

121635378 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121635378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143769600).

121635378 is an abundant number, since it is smaller than the sum of its proper divisors (165903822).

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

121635378 is a wasteful number, since it uses less digits than its factorization.

121635378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1284 (or 1278 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 121635378 is about 11028.8430036881. The cubic root of 121635378 is about 495.4729730904.

The spelling of 121635378 in words is "one hundred twenty-one million, six hundred thirty-five thousand, three hundred seventy-eight".