21004874 has 48 divisors (see below), whose sum is σ = 37202760. Its totient is φ = 8870400.

The previous prime is 21004847. The next prime is 21004883. The reversal of 21004874 is 47840012.

It can be written as a sum of positive squares in 4 ways, for example, as 13741849 + 7263025 = 3707^2 + 2695^2 .

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 287702 + ... + 287774.

Almost surely, 2^21004874 is an apocalyptic number.

21004874 is a deficient number, since it is larger than the sum of its proper divisors (16197886).

21004874 is a wasteful number, since it uses less digits than its factorization.

21004874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 21004874 is about 4583.1074611010. The cubic root of 21004874 is about 275.9137604258.

Adding to 21004874 its reverse (47840012), we get a palindrome (68844886).

The spelling of 21004874 in words is "twenty-one million, four thousand, eight hundred seventy-four".