123211540 has 24 divisors (see below), whose sum is σ = 259291872. Its totient is φ = 49180320.

The previous prime is 123211531. The next prime is 123211547. The reversal of 123211540 is 45112321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123211547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3547 + ... + 16093.

It is an arithmetic number, because the mean of its divisors is an integer number (10803828).

Almost surely, 2^123211540 is an apocalyptic number.

123211540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123211540 is an abundant number, since it is smaller than the sum of its proper divisors (136080332).

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

123211540 is a wasteful number, since it uses less digits than its factorization.

123211540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13047 (or 13045 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 123211540 is about 11100.0693691526. The cubic root of 123211540 is about 497.6039226350.

Adding to 123211540 its reverse (45112321), we get a palindrome (168323861).

It can be divided in two parts, 12321 and 1540, that added together give a triangular number (13861 = T₁₆₆).

The spelling of 123211540 in words is "one hundred twenty-three million, two hundred eleven thousand, five hundred forty".