21003130 has 8 divisors (see below), whose sum is σ = 37805652. Its totient is φ = 8401248.

The previous prime is 21003121. The next prime is 21003139. The reversal of 21003130 is 3130012.

It is an interprime number because it is at equal distance from previous prime (21003121) and next prime (21003139).

It can be written as a sum of positive squares in 2 ways, for example, as 20241001 + 762129 = 4499^2 + 873^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21003130² = 882262939593800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10), and also a Moran number because the ratio is a prime number: 2100313 = 21003130 / (2 + 1 + 0 + 0 + 3 + 1 + 3 + 0).

It is not an unprimeable number, because it can be changed into a prime (21003139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1050147 + ... + 1050166.

Almost surely, 2^21003130 is an apocalyptic number.

21003130 is a deficient number, since it is larger than the sum of its proper divisors (16802522).

21003130 is a wasteful number, since it uses less digits than its factorization.

21003130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2100320.

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 21003130 is about 4582.9171932297. The cubic root of 21003130 is about 275.9061239932.

Adding to 21003130 its reverse (3130012), we get a palindrome (24133142).

The spelling of 21003130 in words is "twenty-one million, three thousand, one hundred thirty".