12221520 has 40 divisors (see below), whose sum is σ = 37887456. Its totient is φ = 3259008.

The previous prime is 12221519. The next prime is 12221527. The reversal of 12221520 is 2512221.

12221520 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×12221520² = 298731102220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 12221520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25222 + ... + 25701.

Almost surely, 2^12221520 is an apocalyptic number.

12221520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12221520 is an abundant number, since it is smaller than the sum of its proper divisors (25665936).

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

12221520 is a wasteful number, since it uses less digits than its factorization.

12221520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50939 (or 50933 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 12221520 is about 3495.9290610652. The cubic root of 12221520 is about 230.3430294134.

Adding to 12221520 its reverse (2512221), we get a palindrome (14733741).

The spelling of 12221520 in words is "twelve million, two hundred twenty-one thousand, five hundred twenty".