12001428 has 36 divisors (see below), whose sum is σ = 30450420. Its totient is φ = 3985536.

The previous prime is 12001427. The next prime is 12001453. The reversal of 12001428 is 82410021.

It can be written as a sum of positive squares in 2 ways, for example, as 7387524 + 4613904 = 2718^2 + 2148^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 12001428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12001421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13576 + ... + 14432.

It is an arithmetic number, because the mean of its divisors is an integer number (845845).

Almost surely, 2^12001428 is an apocalyptic number.

12001428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

12001428 is an abundant number, since it is smaller than the sum of its proper divisors (18448992).

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

12001428 is a wasteful number, since it uses less digits than its factorization.

12001428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256 (or 1251 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 12001428 is about 3464.3077230523. The cubic root of 12001428 is about 228.9519295501.

Adding to 12001428 its reverse (82410021), we get a palindrome (94411449).

It can be divided in two parts, 1200 and 1428, that added together give a triangular number (2628 = T₇₂).

The spelling of 12001428 in words is "twelve million, one thousand, four hundred twenty-eight".