21039008 has 12 divisors (see below), whose sum is σ = 41420610. Its totient is φ = 10519488.

The previous prime is 21039001. The next prime is 21039079. The reversal of 21039008 is 80093012.

It can be written as a sum of positive squares in only one way, i.e., 11478544 + 9560464 = 3388^2 + 3092^2 .

It is not an unprimeable number, because it can be changed into a prime (21039001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328703 + ... + 328766.

Almost surely, 2^21039008 is an apocalyptic number.

It is an amenable number.

21039008 is a deficient number, since it is larger than the sum of its proper divisors (20381602).

21039008 is an equidigital number, since it uses as much as digits as its factorization.

21039008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657479 (or 657471 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21039008 is about 4586.8298420587. The cubic root of 21039008 is about 276.0631375545.

It can be divided in two parts, 2103 and 9008, that added together give a palindrome (11111).

The spelling of 21039008 in words is "twenty-one million, thirty-nine thousand, eight".