21004803 has 6 divisors (see below), whose sum is σ = 30340284. Its totient is φ = 14003196.

The previous prime is 21004799. The next prime is 21004807. The reversal of 21004803 is 30840012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21004799) and next prime (21004807).

It is not a de Polignac number, because 21004803 - 2² = 21004799 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21004807) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1166925 + ... + 1166942.

It is an arithmetic number, because the mean of its divisors is an integer number (5056714).

Almost surely, 2^21004803 is an apocalyptic number.

21004803 is a deficient number, since it is larger than the sum of its proper divisors (9335481).

21004803 is a wasteful number, since it uses less digits than its factorization.

21004803 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333873 (or 2333870 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21004803 is about 4583.0997152582. The cubic root of 21004803 is about 275.9134495472.

Adding to 21004803 its reverse (30840012), we get a palindrome (51844815).

It can be divided in two parts, 2100 and 4803, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 21004803 in words is "twenty-one million, four thousand, eight hundred three".