21071116 has 24 divisors (see below), whose sum is σ = 40649616. Its totient is φ = 9477120.

The previous prime is 21071111. The next prime is 21071119. The reversal of 21071116 is 61117012.

It is a junction number, because it is equal to n+sod(n) for n = 21071093 and 21071102.

It is not an unprimeable number, because it can be changed into a prime (21071111) 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, 1800 + ... + 6736.

It is an arithmetic number, because the mean of its divisors is an integer number (1693734).

Almost surely, 2^21071116 is an apocalyptic number.

It is an amenable number.

21071116 is a deficient number, since it is larger than the sum of its proper divisors (19578500).

21071116 is a wasteful number, since it uses less digits than its factorization.

21071116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5049 (or 5047 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 19.

The square root of 21071116 is about 4590.3285285478. The cubic root of 21071116 is about 276.2035011108.

Adding to 21071116 its reverse (61117012), we get a palindrome (82188128).

It can be divided in two parts, 2107 and 1116, that added together give a palindrome (3223).

The spelling of 21071116 in words is "twenty-one million, seventy-one thousand, one hundred sixteen".