21163516 has 12 divisors (see below), whose sum is σ = 40403160. Its totient is φ = 9619760.

The previous prime is 21163507. The next prime is 21163531. The reversal of 21163516 is 61536112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240451 + ... + 240538.

It is an arithmetic number, because the mean of its divisors is an integer number (3366930).

Almost surely, 2^21163516 is an apocalyptic number.

It is an amenable number.

21163516 is a deficient number, since it is larger than the sum of its proper divisors (19239644).

21163516 is a wasteful number, since it uses less digits than its factorization.

21163516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 481004 (or 481002 counting only the distinct ones).

The product of its digits is 1080, while the sum is 25.

The square root of 21163516 is about 4600.3821580386. The cubic root of 21163516 is about 276.6066436457.

Adding to 21163516 its reverse (61536112), we get a palindrome (82699628).

The spelling of 21163516 in words is "twenty-one million, one hundred sixty-three thousand, five hundred sixteen".