121638828 has 24 divisors (see below), whose sum is σ = 287418880. Its totient is φ = 40032720.

The previous prime is 121638827. The next prime is 121638851. The reversal of 121638828 is 828836121.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (121638827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63208 + ... + 65103.

Almost surely, 2^121638828 is an apocalyptic number.

It is an amenable number.

121638828 is an abundant number, since it is smaller than the sum of its proper divisors (165780052).

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

121638828 is a wasteful number, since it uses less digits than its factorization.

121638828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128397 (or 128395 counting only the distinct ones).

The product of its digits is 36864, while the sum is 39.

The square root of 121638828 is about 11028.9994106446. Note that the first 3 decimals coincide. The cubic root of 121638828 is about 495.4776574885.

The spelling of 121638828 in words is "one hundred twenty-one million, six hundred thirty-eight thousand, eight hundred twenty-eight".