12155724 has 72 divisors (see below), whose sum is σ = 36676080. Its totient is φ = 3471552.

The previous prime is 12155723. The next prime is 12155747. The reversal of 12155724 is 42755121.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (12155723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4144 + ... + 6440.

It is an arithmetic number, because the mean of its divisors is an integer number (509390).

Almost surely, 2^12155724 is an apocalyptic number.

12155724 is a gapful number since it is divisible by the number (14) 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 12155724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18338040).

12155724 is an abundant number, since it is smaller than the sum of its proper divisors (24520356).

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

12155724 is a wasteful number, since it uses less digits than its factorization.

12155724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2324 (or 2309 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 12155724 is about 3486.5059873748. The cubic root of 12155724 is about 229.9289257391.

The spelling of 12155724 in words is "twelve million, one hundred fifty-five thousand, seven hundred twenty-four".