123540520 has 64 divisors (see below), whose sum is σ = 284497920. Its totient is φ = 48271104.

The previous prime is 123540517. The next prime is 123540523. The reversal of 123540520 is 25045321.

It is an interprime number because it is at equal distance from previous prime (123540517) and next prime (123540523).

It is a junction number, because it is equal to n+sod(n) for n = 123540491 and 123540500.

It is not an unprimeable number, because it can be changed into a prime (123540523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 421494 + ... + 421786.

It is an arithmetic number, because the mean of its divisors is an integer number (4445280).

Almost surely, 2^123540520 is an apocalyptic number.

123540520 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 123540520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142248960).

123540520 is an abundant number, since it is smaller than the sum of its proper divisors (160957400).

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

123540520 is a wasteful number, since it uses less digits than its factorization.

123540520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 123540520 is about 11114.8783169228. The cubic root of 123540520 is about 498.0464035296.

Adding to 123540520 its reverse (25045321), we get a palindrome (148585841).

The spelling of 123540520 in words is "one hundred twenty-three million, five hundred forty thousand, five hundred twenty".