21130760 has 48 divisors (see below), whose sum is σ = 55311660. Its totient is φ = 7244160.

The previous prime is 21130741. The next prime is 21130783. The reversal of 21130760 is 6703112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20448484 + 682276 = 4522^2 + 826^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3431 + ... + 7350.

Almost surely, 2^21130760 is an apocalyptic number.

21130760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130760 is an abundant number, since it is smaller than the sum of its proper divisors (34180900).

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

21130760 is a wasteful number, since it uses less digits than its factorization.

21130760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10806 (or 10795 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 21130760 is about 4596.8206403992. The cubic root of 21130760 is about 276.4638632472.

Adding to 21130760 its reverse (6703112), we get a palindrome (27833872).

The spelling of 21130760 in words is "twenty-one million, one hundred thirty thousand, seven hundred sixty".