21130516 has 24 divisors (see below), whose sum is σ = 40459104. Its totient is φ = 9576480.

The previous prime is 21130511. The next prime is 21130573. The reversal of 21130516 is 61503112.

It is a junction number, because it is equal to n+sod(n) for n = 21130493 and 21130502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24346 + ... + 25198.

It is an arithmetic number, because the mean of its divisors is an integer number (1685796).

Almost surely, 2^21130516 is an apocalyptic number.

It is an amenable number.

21130516 is a deficient number, since it is larger than the sum of its proper divisors (19328588).

21130516 is a wasteful number, since it uses less digits than its factorization.

21130516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1431 (or 1429 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 21130516 is about 4596.7941002399. The cubic root of 21130516 is about 276.4627991202.

Adding to 21130516 its reverse (61503112), we get a palindrome (82633628).

The spelling of 21130516 in words is "twenty-one million, one hundred thirty thousand, five hundred sixteen".