121128550 has 24 divisors (see below), whose sum is σ = 226956456. Its totient is φ = 48095040.

The previous prime is 121128529. The next prime is 121128569. The reversal of 121128550 is 55821121.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1992 + ... + 15691.

It is an arithmetic number, because the mean of its divisors is an integer number (9456519).

Almost surely, 2^121128550 is an apocalyptic number.

121128550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121128550 is a deficient number, since it is larger than the sum of its proper divisors (105827906).

121128550 is a wasteful number, since it uses less digits than its factorization.

121128550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17832 (or 17827 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 25.

The square root of 121128550 is about 11005.8416306978. The cubic root of 121128550 is about 494.7838392311.

Adding to 121128550 its reverse (55821121), we get a palindrome (176949671).

The spelling of 121128550 in words is "one hundred twenty-one million, one hundred twenty-eight thousand, five hundred fifty".