21230004 has 12 divisors (see below), whose sum is σ = 49536704. Its totient is φ = 7076664.

The previous prime is 21229979. The next prime is 21230017. The reversal of 21230004 is 40003212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Harshad number since it is a multiple of its sum of digits (12), and also a Moran number because the ratio is a prime number: 1769167 = 21230004 / (2 + 1 + 2 + 3 + 0 + 0 + 0 + 4).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 884572 + ... + 884595.

Almost surely, 2^21230004 is an apocalyptic number.

It is an amenable number.

21230004 is an abundant number, since it is smaller than the sum of its proper divisors (28306700).

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

21230004 is a wasteful number, since it uses less digits than its factorization.

21230004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1769174 (or 1769172 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21230004 is about 4607.6028474685. The cubic root of 21230004 is about 276.8960063519.

Adding to 21230004 its reverse (40003212), we get a palindrome (61233216).

The spelling of 21230004 in words is "twenty-one million, two hundred thirty thousand, four".