21004460 has 24 divisors (see below), whose sum is σ = 44195760. Its totient is φ = 8385344.

The previous prime is 21004457. The next prime is 21004463. The reversal of 21004460 is 6440012.

It is an interprime number because it is at equal distance from previous prime (21004457) and next prime (21004463).

It is not an unprimeable number, because it can be changed into a prime (21004463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18386 + ... + 19494.

It is an arithmetic number, because the mean of its divisors is an integer number (1841490).

Almost surely, 2^21004460 is an apocalyptic number.

21004460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004460 is an abundant number, since it is smaller than the sum of its proper divisors (23191300).

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

21004460 is a wasteful number, since it uses less digits than its factorization.

21004460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2065 (or 2063 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21004460 is about 4583.0622950163. The cubic root of 21004460 is about 275.9119476870.

Adding to 21004460 its reverse (6440012), we get a palindrome (27444472).

The spelling of 21004460 in words is "twenty-one million, four thousand, four hundred sixty".