12155550 has 96 divisors (see below), whose sum is σ = 33747840. Its totient is φ = 2870400.

The previous prime is 12155537. The next prime is 12155567. The reversal of 12155550 is 5555121.

12155550 = 126² + 127² + ... + 337².

It is a self number, because there is not a number n which added to its sum of digits gives 12155550.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 87381 + ... + 87519.

It is an arithmetic number, because the mean of its divisors is an integer number (351540).

Almost surely, 2^12155550 is an apocalyptic number.

12155550 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 12155550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16873920).

12155550 is an abundant number, since it is smaller than the sum of its proper divisors (21592290).

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

12155550 is a wasteful number, since it uses less digits than its factorization.

12155550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 1250, while the sum is 24.

The square root of 12155550 is about 3486.4810339367. The cubic root of 12155550 is about 229.9278286476.

The spelling of 12155550 in words is "twelve million, one hundred fifty-five thousand, five hundred fifty".