121550520 has 128 divisors (see below), whose sum is σ = 448842240. Its totient is φ = 25643520.

The previous prime is 121550503. The next prime is 121550521. The reversal of 121550520 is 25055121.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121550521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5355 + ... + 16485.

It is an arithmetic number, because the mean of its divisors is an integer number (3506580).

Almost surely, 2^121550520 is an apocalyptic number.

121550520 is a gapful number since it is divisible by the number (10) 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 121550520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224421120).

121550520 is an abundant number, since it is smaller than the sum of its proper divisors (327291720).

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

121550520 is a wasteful number, since it uses less digits than its factorization.

121550520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11165 (or 11161 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 121550520 is about 11024.9952380942. The cubic root of 121550520 is about 495.3577252969.

The spelling of 121550520 in words is "one hundred twenty-one million, five hundred fifty thousand, five hundred twenty".