12421520 has 20 divisors (see below), whose sum is σ = 28880220. Its totient is φ = 4968576.

The previous prime is 12421517. The next prime is 12421537. The reversal of 12421520 is 2512421.

It can be written as a sum of positive squares in 2 ways, for example, as 1478656 + 10942864 = 1216^2 + 3308^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×12421520² = 308588318220800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77555 + ... + 77714.

It is an arithmetic number, because the mean of its divisors is an integer number (1444011).

Almost surely, 2^12421520 is an apocalyptic number.

12421520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12421520 is an abundant number, since it is smaller than the sum of its proper divisors (16458700).

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

12421520 is a wasteful number, since it uses less digits than its factorization.

12421520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155282 (or 155276 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 12421520 is about 3524.4176823980. The cubic root of 12421520 is about 231.5927258005.

Adding to 12421520 its reverse (2512421), we get a palindrome (14933941).

Subtracting from 12421520 its reverse (2512421), we obtain a palindrome (9909099).

The spelling of 12421520 in words is "twelve million, four hundred twenty-one thousand, five hundred twenty".