21070980 has 108 divisors (see below), whose sum is σ = 74381580. Its totient is φ = 4814208.

The previous prime is 21070969. The next prime is 21070991. The reversal of 21070980 is 8907012.

It is an interprime number because it is at equal distance from previous prime (21070969) and next prime (21070991).

It can be written as a sum of positive squares in 2 ways, for example, as 6140484 + 14930496 = 2478^2 + 3864^2 .

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 35 ways as a sum of consecutive naturals, for example, 7626 + ... + 10014.

Almost surely, 2^21070980 is an apocalyptic number.

21070980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21070980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37190790).

21070980 is an abundant number, since it is smaller than the sum of its proper divisors (53310600).

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

21070980 is a wasteful number, since it uses less digits than its factorization.

21070980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2418 (or 2406 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 21070980 is about 4590.3137147694. The cubic root of 21070980 is about 276.2029068731.

Adding to 21070980 its reverse (8907012), we get a palindrome (29977992).

The spelling of 21070980 in words is "twenty-one million, seventy thousand, nine hundred eighty".