12021645 has 32 divisors (see below), whose sum is σ = 20127744. Its totient is φ = 6120000.

The previous prime is 12021641. The next prime is 12021671. The reversal of 12021645 is 54612021.

It is not a de Polignac number, because 12021645 - 2² = 12021641 is a prime.

It is a super-3 number, since 3×12021645³ (a number of 22 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12021641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47770 + ... + 48020.

It is an arithmetic number, because the mean of its divisors is an integer number (628992).

Almost surely, 2^12021645 is an apocalyptic number.

12021645 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12021645 is a deficient number, since it is larger than the sum of its proper divisors (8106099).

12021645 is a wasteful number, since it uses less digits than its factorization.

12021645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 12021645 is about 3467.2243942381. The cubic root of 12021645 is about 229.0804177180.

Adding to 12021645 its reverse (54612021), we get a palindrome (66633666).

The spelling of 12021645 in words is "twelve million, twenty-one thousand, six hundred forty-five".