12121520 has 40 divisors (see below), whose sum is σ = 28335984. Its totient is φ = 4822272.

The previous prime is 12121517. The next prime is 12121531. The reversal of 12121520 is 2512121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×12121520² = 293862494220800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 12121495 and 12121504.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21887 + ... + 22433.

Almost surely, 2^12121520 is an apocalyptic number.

12121520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121520 is an abundant number, since it is smaller than the sum of its proper divisors (16214464).

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

12121520 is a wasteful number, since it uses less digits than its factorization.

12121520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 837 (or 831 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 12121520 is about 3481.5973345578. The cubic root of 12121520 is about 229.7130637319.

Adding to 12121520 its reverse (2512121), we get a palindrome (14633641).

It can be divided in two parts, 1212 and 1520, that multiplied together give a triangular number (1842240 = T₁₉₁₉).

The spelling of 12121520 in words is "twelve million, one hundred twenty-one thousand, five hundred twenty".