12213540 has 36 divisors (see below), whose sum is σ = 37048284. Its totient is φ = 3256896.

The previous prime is 12213527. The next prime is 12213541. The reversal of 12213540 is 4531221.

12213540 is a `hidden beast` number, since 122 + 1 + 3 + 540 = 666.

12213540 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 7096896 + 5116644 = 2664^2 + 2262^2 .

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 not an unprimeable number, because it can be changed into a prime (12213541) 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, 33747 + ... + 34106.

It is an arithmetic number, because the mean of its divisors is an integer number (1029119).

Almost surely, 2^12213540 is an apocalyptic number.

12213540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12213540 is an abundant number, since it is smaller than the sum of its proper divisors (24834744).

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

12213540 is a wasteful number, since it uses less digits than its factorization.

12213540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67868 (or 67863 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 12213540 is about 3494.7875471908. The cubic root of 12213540 is about 230.2928845981.

Adding to 12213540 its reverse (4531221), we get a palindrome (16744761).

It can be divided in two parts, 1221 and 3540, that added together give a square (4761 = 69²).

The spelling of 12213540 in words is "twelve million, two hundred thirteen thousand, five hundred forty".