21225412 has 24 divisors (see below), whose sum is σ = 41743296. Its totient is φ = 9369888.

The previous prime is 21225403. The next prime is 21225431. The reversal of 21225412 is 21452212.

It is a super-2 number, since 2×21225412² = 901036229139488, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21225412.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7678 + ... + 10069.

It is an arithmetic number, because the mean of its divisors is an integer number (1739304).

Almost surely, 2^21225412 is an apocalyptic number.

It is an amenable number.

21225412 is a deficient number, since it is larger than the sum of its proper divisors (20517884).

21225412 is a wasteful number, since it uses less digits than its factorization.

21225412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17787 (or 17785 counting only the distinct ones).

The product of its digits is 320, while the sum is 19.

The square root of 21225412 is about 4607.1045136832. The cubic root of 21225412 is about 276.8760409271.

Adding to 21225412 its reverse (21452212), we get a palindrome (42677624).

The spelling of 21225412 in words is "twenty-one million, two hundred twenty-five thousand, four hundred twelve".