121638258 has 48 divisors (see below), whose sum is σ = 304611840. Its totient is φ = 34360128.

The previous prime is 121638227. The next prime is 121638269. The reversal of 121638258 is 852836121.

It is a happy number.

121638258 is a `hidden beast` number, since 12 + 1 + 638 + 2 + 5 + 8 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5791 + ... + 16637.

It is an arithmetic number, because the mean of its divisors is an integer number (6346080).

Almost surely, 2^121638258 is an apocalyptic number.

121638258 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 121638258, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152305920).

121638258 is an abundant number, since it is smaller than the sum of its proper divisors (182973582).

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

121638258 is a wasteful number, since it uses less digits than its factorization.

121638258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10951 (or 10948 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 121638258 is about 11028.9735696483. The cubic root of 121638258 is about 495.4768835506.

The spelling of 121638258 in words is "one hundred twenty-one million, six hundred thirty-eight thousand, two hundred fifty-eight".