123212540 has 48 divisors (see below), whose sum is σ = 283409280. Its totient is φ = 44623680.

The previous prime is 123212513. The next prime is 123212567. The reversal of 123212540 is 45212321.

It is an interprime number because it is at equal distance from previous prime (123212513) and next prime (123212567).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61271 + ... + 63249.

It is an arithmetic number, because the mean of its divisors is an integer number (5904360).

Almost surely, 2^123212540 is an apocalyptic number.

123212540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123212540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141704640).

123212540 is an abundant number, since it is smaller than the sum of its proper divisors (160196740).

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

123212540 is a wasteful number, since it uses less digits than its factorization.

123212540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2282 (or 2280 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 123212540 is about 11100.1144138248. The cubic root of 123212540 is about 497.6052688362.

Adding to 123212540 its reverse (45212321), we get a palindrome (168424861).

The spelling of 123212540 in words is "one hundred twenty-three million, two hundred twelve thousand, five hundred forty".