21004282 has 16 divisors (see below), whose sum is σ = 35926632. Its totient is φ = 9123840.

The previous prime is 21004273. The next prime is 21004301. The reversal of 21004282 is 28240012.

It can be written as a sum of positive squares in 4 ways, for example, as 20061441 + 942841 = 4479^2 + 971^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23319 + ... + 24202.

Almost surely, 2^21004282 is an apocalyptic number.

21004282 is a deficient number, since it is larger than the sum of its proper divisors (14922350).

21004282 is a wasteful number, since it uses less digits than its factorization.

21004282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47553.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 21004282 is about 4583.0428756450. The cubic root of 21004282 is about 275.9111682896.

Adding to 21004282 its reverse (28240012), we get a palindrome (49244294).

The spelling of 21004282 in words is "twenty-one million, four thousand, two hundred eighty-two".