21030080 has 28 divisors (see below), whose sum is σ = 50078640. Its totient is φ = 8411904.

The previous prime is 21030049. The next prime is 21030083. The reversal of 21030080 is 8003012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030083) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32540 + ... + 33179.

Almost surely, 2^21030080 is an apocalyptic number.

21030080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21030080 is an abundant number, since it is smaller than the sum of its proper divisors (29048560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21030080 is an equidigital number, since it uses as much as digits as its factorization.

21030080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65736 (or 65726 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21030080 is about 4585.8565175984. The cubic root of 21030080 is about 276.0240824747.

Adding to 21030080 its reverse (8003012), we get a palindrome (29033092).

The spelling of 21030080 in words is "twenty-one million, thirty thousand, eighty".