12621220 has 12 divisors (see below), whose sum is σ = 26504604. Its totient is φ = 5048480.

The previous prime is 12621197. The next prime is 12621241. The reversal of 12621220 is 2212621.

It can be written as a sum of positive squares in 2 ways, for example, as 9771876 + 2849344 = 3126^2 + 1688^2 .

It is a junction number, because it is equal to n+sod(n) for n = 12621194 and 12621203.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 315511 + ... + 315550.

It is an arithmetic number, because the mean of its divisors is an integer number (2208717).

Almost surely, 2^12621220 is an apocalyptic number.

12621220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12621220 is an abundant number, since it is smaller than the sum of its proper divisors (13883384).

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

12621220 is a wasteful number, since it uses less digits than its factorization.

12621220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631070 (or 631068 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 12621220 is about 3552.6356413232. The cubic root of 12621220 is about 232.8272341320.

Adding to 12621220 its reverse (2212621), we get a palindrome (14833841).

The spelling of 12621220 in words is "twelve million, six hundred twenty-one thousand, two hundred twenty".