12001356 has 72 divisors (see below), whose sum is σ = 31921344. Its totient is φ = 3797760.

The previous prime is 12001349. The next prime is 12001361. The reversal of 12001356 is 65310021.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69286 + ... + 69458.

It is an arithmetic number, because the mean of its divisors is an integer number (443352).

Almost surely, 2^12001356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12001356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15960672).

12001356 is an abundant number, since it is smaller than the sum of its proper divisors (19919988).

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

12001356 is a wasteful number, since it uses less digits than its factorization.

12001356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271 (or 266 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 12001356 is about 3464.2973313502. The cubic root of 12001356 is about 228.9514716998.

Adding to 12001356 its reverse (65310021), we get a palindrome (77311377).

It can be divided in two parts, 1200 and 1356, that added together give a triangular number (2556 = T₇₁).

The spelling of 12001356 in words is "twelve million, one thousand, three hundred fifty-six".