21220304 has 20 divisors (see below), whose sum is σ = 46988064. Its totient is φ = 9094368.

The previous prime is 21220261. The next prime is 21220313. The reversal of 21220304 is 40302212.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

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, 94622 + ... + 94845.

Almost surely, 2^21220304 is an apocalyptic number.

It is an amenable number.

21220304 is an abundant number, since it is smaller than the sum of its proper divisors (25767760).

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

21220304 is a wasteful number, since it uses less digits than its factorization.

21220304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189482 (or 189476 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21220304 is about 4606.5501191239. The cubic root of 21220304 is about 276.8538286172.

Adding to 21220304 its reverse (40302212), we get a palindrome (61522516).

The spelling of 21220304 in words is "twenty-one million, two hundred twenty thousand, three hundred four".