123213618 has 48 divisors (see below), whose sum is σ = 293862816. Its totient is φ = 37000320.

The previous prime is 123213617. The next prime is 123213667. The reversal of 123213618 is 816312321.

It is a happy number.

123213618 is a `hidden beast` number, since 1 + 2 + 32 + 13 + 618 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 123213591 and 123213600.

It is not an unprimeable number, because it can be changed into a prime (123213611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19621 + ... + 25127.

It is an arithmetic number, because the mean of its divisors is an integer number (6122142).

Almost surely, 2^123213618 is an apocalyptic number.

123213618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 123213618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146931408).

123213618 is an abundant number, since it is smaller than the sum of its proper divisors (170649198).

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

123213618 is a wasteful number, since it uses less digits than its factorization.

123213618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5639 (or 5636 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 123213618 is about 11100.1629717766. The cubic root of 123213618 is about 497.6067200329.

Adding to 123213618 its reverse (816312321), we get a palindrome (939525939).

The spelling of 123213618 in words is "one hundred twenty-three million, two hundred thirteen thousand, six hundred eighteen".