123521520 has 80 divisors (see below), whose sum is σ = 392287392. Its totient is φ = 32133120.

The previous prime is 123521509. The next prime is 123521533. The reversal of 123521520 is 25125321.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×123521520² = 30515131806220800, which contains 22 as substring.

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, 3564 + ... + 16116.

Almost surely, 2^123521520 is an apocalyptic number.

123521520 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 123521520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196143696).

123521520 is an abundant number, since it is smaller than the sum of its proper divisors (268765872).

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

123521520 is a wasteful number, since it uses less digits than its factorization.

123521520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12610 (or 12604 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 123521520 is about 11114.0235738458. The cubic root of 123521520 is about 498.0208697565.

Adding to 123521520 its reverse (25125321), we get a palindrome (148646841).

The spelling of 123521520 in words is "one hundred twenty-three million, five hundred twenty-one thousand, five hundred twenty".