121535550 has 72 divisors (see below), whose sum is σ = 345754656. Its totient is φ = 30501120.

The previous prime is 121535539. The next prime is 121535551. The reversal of 121535550 is 55535121.

121535550 is a `hidden beast` number, since 121 + 535 + 5 + 5 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121535551) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 294 + ... + 15593.

It is an arithmetic number, because the mean of its divisors is an integer number (4802148).

Almost surely, 2^121535550 is an apocalyptic number.

121535550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121535550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172877328).

121535550 is an abundant number, since it is smaller than the sum of its proper divisors (224219106).

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

121535550 is a wasteful number, since it uses less digits than its factorization.

121535550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15922 (or 15914 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The square root of 121535550 is about 11024.3163053316. The cubic root of 121535550 is about 495.3373885964.

The spelling of 121535550 in words is "one hundred twenty-one million, five hundred thirty-five thousand, five hundred fifty".