21361516 has 24 divisors (see below), whose sum is σ = 42189840. Its totient is φ = 9374400.

The previous prime is 21361489. The next prime is 21361519. The reversal of 21361516 is 61516312.

It is not an unprimeable number, because it can be changed into a prime (21361519) 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, 7095 + ... + 9646.

It is an arithmetic number, because the mean of its divisors is an integer number (1757910).

Almost surely, 2^21361516 is an apocalyptic number.

It is an amenable number.

21361516 is a deficient number, since it is larger than the sum of its proper divisors (20828324).

21361516 is a wasteful number, since it uses less digits than its factorization.

21361516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16785 (or 16783 counting only the distinct ones).

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

The square root of 21361516 is about 4621.8520097467. The cubic root of 21361516 is about 277.4665858098.

Adding to 21361516 its reverse (61516312), we get a palindrome (82877828).

The spelling of 21361516 in words is "twenty-one million, three hundred sixty-one thousand, five hundred sixteen".